2021-03-14 11:12:46

by syzbot

[permalink] [raw]
Subject: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

Hello,

syzbot found the following issue on:

HEAD commit: 280d542f Merge tag 'drm-fixes-2021-03-05' of git://anongit..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15ade5aed00000
kernel config: https://syzkaller.appspot.com/x/.config?x=952047a9dbff6a6a
dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

==================================================================
BUG: KASAN: use-after-free in bdev_nr_sectors include/linux/genhd.h:266 [inline]
BUG: KASAN: use-after-free in disk_part_iter_next+0x49d/0x530 block/genhd.c:207
Read of size 8 at addr ffff88804b0022e8 by task systemd-udevd/9804

CPU: 1 PID: 9804 Comm: systemd-udevd Not tainted 5.12.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0xfa/0x151 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:232
__kasan_report mm/kasan/report.c:399 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
bdev_nr_sectors include/linux/genhd.h:266 [inline]
disk_part_iter_next+0x49d/0x530 block/genhd.c:207
blk_drop_partitions+0x10a/0x180 block/partitions/core.c:543
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1237
__loop_clr_fd+0x7c7/0xff0 drivers/block/loop.c:1271
lo_release+0x1ac/0x1f0 drivers/block/loop.c:1923
__blkdev_put+0x54e/0x800 fs/block_dev.c:1579
blkdev_put+0x92/0x580 fs/block_dev.c:1632
blkdev_close+0x8c/0xb0 fs/block_dev.c:1640
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f8141652270
Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24
RSP: 002b:00007ffe05d67588 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f8141652270
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007f814250c710 R08: 000055e767969790 R09: 000055e767968300
R10: 00007f814250c8c0 R11: 0000000000000246 R12: 0000000000000000
R13: 000055e767979eb0 R14: 0000000000000003 R15: 000000000000000e

Allocated by task 9582:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:427 [inline]
__kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:460
kasan_slab_alloc include/linux/kasan.h:223 [inline]
slab_post_alloc_hook mm/slab.h:516 [inline]
slab_alloc mm/slab.c:3325 [inline]
kmem_cache_alloc+0x1c3/0x4f0 mm/slab.c:3502
bdev_alloc_inode+0x18/0x80 fs/block_dev.c:786
alloc_inode+0x61/0x230 fs/inode.c:234
new_inode_pseudo fs/inode.c:928 [inline]
new_inode+0x27/0x2f0 fs/inode.c:957
bdev_alloc+0x20/0x2f0 fs/block_dev.c:876
add_partition+0x1ab/0x8a0 block/partitions/core.c:348
bdev_add_partition+0xb6/0x130 block/partitions/core.c:451
blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43
blkpg_ioctl block/ioctl.c:60 [inline]
blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548
block_ioctl+0xf9/0x140 fs/block_dev.c:1658
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 8676:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
____kasan_slab_free mm/kasan/common.c:360 [inline]
____kasan_slab_free mm/kasan/common.c:325 [inline]
__kasan_slab_free+0xc7/0x100 mm/kasan/common.c:367
kasan_slab_free include/linux/kasan.h:199 [inline]
__cache_free mm/slab.c:3440 [inline]
kmem_cache_free+0x6f/0x1d0 mm/slab.c:3733
i_callback+0x3f/0x70 fs/inode.c:223
rcu_do_batch kernel/rcu/tree.c:2559 [inline]
rcu_core+0x722/0x1280 kernel/rcu/tree.c:2794
__do_softirq+0x29b/0x9f6 kernel/softirq.c:345

Last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xa4/0xd0 mm/kasan/generic.c:345
__call_rcu kernel/rcu/tree.c:3039 [inline]
call_rcu+0xb1/0x700 kernel/rcu/tree.c:3114
destroy_inode+0x129/0x1b0 fs/inode.c:289
iput_final fs/inode.c:1654 [inline]
iput.part.0+0x57e/0x810 fs/inode.c:1680
iput+0x58/0x70 fs/inode.c:1670
disk_part_iter_exit block/genhd.c:236 [inline]
disk_part_iter_next+0x9a/0x530 block/genhd.c:203
blk_drop_partitions+0x10a/0x180 block/partitions/core.c:543
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1237
loop_reread_partitions+0x29/0x50 drivers/block/loop.c:655
loop_set_status+0x704/0x1050 drivers/block/loop.c:1418
loop_set_status64 drivers/block/loop.c:1538 [inline]
lo_ioctl+0x4ca/0x1620 drivers/block/loop.c:1706
blkdev_ioctl+0x2a1/0x6d0 block/ioctl.c:583
block_ioctl+0xf9/0x140 fs/block_dev.c:1658
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88804b0022c0
which belongs to the cache bdev_cache of size 2792
The buggy address is located 40 bytes inside of
2792-byte region [ffff88804b0022c0, ffff88804b002da8)
The buggy address belongs to the page:
page:00000000708f9251 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804b002fff pfn:0x4b002
flags: 0x4fff00000000200(slab)
raw: 04fff00000000200 ffffea00010ecd48 ffffea00012c2fc8 ffff888010b95700
raw: ffff88804b002fff ffff88804b0022c0 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88804b002180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88804b002200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804b002280: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
^
ffff88804b002300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88804b002380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email protected].

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.


2021-03-20 20:59:00

by syzbot

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

syzbot has found a reproducer for the following issue on:

HEAD commit: 1c273e10 Merge tag 'zonefs-5.12-rc4' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16889906d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=6abda3336c698a07
dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13dfe8bed00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=155a117cd00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

==================================================================
BUG: KASAN: use-after-free in bdev_nr_sectors include/linux/genhd.h:266 [inline]
BUG: KASAN: use-after-free in disk_part_iter_next+0x49d/0x530 block/genhd.c:206
Read of size 8 at addr ffff88803268d0a8 by task syz-executor193/10255

CPU: 0 PID: 10255 Comm: syz-executor193 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232
__kasan_report mm/kasan/report.c:399 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
bdev_nr_sectors include/linux/genhd.h:266 [inline]
disk_part_iter_next+0x49d/0x530 block/genhd.c:206
partition_overlaps+0x96/0x200 block/partitions/core.c:425
bdev_add_partition+0x66/0x130 block/partitions/core.c:444
blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43
blkpg_ioctl block/ioctl.c:60 [inline]
blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x445739
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffca5947308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000445739
RDX: 0000000020000240 RSI: 0000000000001269 RDI: 0000000000000003
RBP: 00007ffca5947380 R08: 000000000000ece4 R09: 000000000000ece4
R10: 0023706f6f6c2f76 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffca5947370 R14: 00007ffca5947360 R15: 00007ffca594732c

Allocated by task 10192:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:427 [inline]
__kasan_slab_alloc+0x75/0x90 mm/kasan/common.c:460
kasan_slab_alloc include/linux/kasan.h:223 [inline]
slab_post_alloc_hook mm/slab.h:516 [inline]
slab_alloc_node mm/slub.c:2907 [inline]
slab_alloc mm/slub.c:2915 [inline]
kmem_cache_alloc+0x155/0x370 mm/slub.c:2920
bdev_alloc_inode+0x18/0x80 fs/block_dev.c:795
alloc_inode+0x61/0x230 fs/inode.c:234
new_inode_pseudo fs/inode.c:928 [inline]
new_inode+0x27/0x2f0 fs/inode.c:957
bdev_alloc+0x20/0x2f0 fs/block_dev.c:885
add_partition+0x1ab/0x880 block/partitions/core.c:346
bdev_add_partition+0xb6/0x130 block/partitions/core.c:449
blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43
blkpg_ioctl block/ioctl.c:60 [inline]
blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 0:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
____kasan_slab_free mm/kasan/common.c:360 [inline]
____kasan_slab_free mm/kasan/common.c:325 [inline]
__kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367
kasan_slab_free include/linux/kasan.h:199 [inline]
slab_free_hook mm/slub.c:1562 [inline]
slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600
slab_free mm/slub.c:3161 [inline]
kmem_cache_free+0x8a/0x740 mm/slub.c:3177
i_callback+0x3f/0x70 fs/inode.c:223
rcu_do_batch kernel/rcu/tree.c:2559 [inline]
rcu_core+0x74a/0x12f0 kernel/rcu/tree.c:2794
__do_softirq+0x29b/0x9f6 kernel/softirq.c:345

Last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345
__call_rcu kernel/rcu/tree.c:3039 [inline]
call_rcu+0xb1/0x740 kernel/rcu/tree.c:3114
destroy_inode+0x129/0x1b0 fs/inode.c:289
iput_final fs/inode.c:1654 [inline]
iput.part.0+0x57e/0x810 fs/inode.c:1680
iput+0x58/0x70 fs/inode.c:1670
disk_part_iter_exit block/genhd.c:235 [inline]
disk_part_iter_next+0x9a/0x530 block/genhd.c:202
blk_drop_partitions+0x10a/0x180 block/partitions/core.c:541
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1246
__loop_clr_fd+0x7c7/0xff0 drivers/block/loop.c:1271
lo_release+0x1ac/0x1f0 drivers/block/loop.c:1923
__blkdev_put+0x54e/0x800 fs/block_dev.c:1588
blkdev_put+0x92/0x580 fs/block_dev.c:1641
blkdev_close+0x8c/0xb0 fs/block_dev.c:1649
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x44/0xae

Second to last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345
__call_rcu kernel/rcu/tree.c:3039 [inline]
call_rcu+0xb1/0x740 kernel/rcu/tree.c:3114
destroy_inode+0x129/0x1b0 fs/inode.c:289
iput_final fs/inode.c:1654 [inline]
iput.part.0+0x57e/0x810 fs/inode.c:1680
iput+0x58/0x70 fs/inode.c:1670
disk_part_iter_exit block/genhd.c:235 [inline]
disk_part_iter_next+0x9a/0x530 block/genhd.c:202
blk_drop_partitions+0x10a/0x180 block/partitions/core.c:541
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1246
__blkdev_get+0x86c/0xa30 fs/block_dev.c:1350
blkdev_get_by_dev fs/block_dev.c:1454 [inline]
blkdev_get_by_dev+0x26c/0x600 fs/block_dev.c:1422
blkdev_reread_part block/ioctl.c:100 [inline]
blkdev_common_ioctl+0x137e/0x17e0 block/ioctl.c:508
blkdev_ioctl+0x1ef/0x6d0 block/ioctl.c:577
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88803268d080
which belongs to the cache bdev_cache of size 2792
The buggy address is located 40 bytes inside of
2792-byte region [ffff88803268d080, ffff88803268db68)
The buggy address belongs to the page:
page:ffffea0000c9a200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32688
head:ffffea0000c9a200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 ffffea0005110a00 0000000200000002 ffff8880109bdb40
raw: 0000000000000000 00000000800b000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88803268cf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
ffff88803268d000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88803268d080: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88803268d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88803268d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

2021-03-21 12:41:58

by syzbot

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

syzbot has bisected this issue to:

commit a33df75c6328bf40078b35f2040d8e54d574c357
Author: Christoph Hellwig <[email protected]>
Date: Sun Jan 24 10:02:41 2021 +0000

block: use an xarray for disk->part_tbl

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17989906d00000
start commit: 1c273e10 Merge tag 'zonefs-5.12-rc4' of git://git.kernel.o..
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=14589906d00000
console output: https://syzkaller.appspot.com/x/log.txt?x=10589906d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=6abda3336c698a07
dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13dfe8bed00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=155a117cd00000

Reported-by: [email protected]
Fixes: a33df75c6328 ("block: use an xarray for disk->part_tbl")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

2021-03-21 23:05:55

by Bart Van Assche

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

On 3/14/21 4:08 AM, syzbot wrote:
> syzbot found the following issue on:
>
> HEAD commit: 280d542f Merge tag 'drm-fixes-2021-03-05' of git://anongit..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15ade5aed00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=952047a9dbff6a6a
> dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139

#syz test: https://github.com/bvanassche/linux a5f35387ebdc

2021-03-21 23:07:40

by syzbot

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Read in disk_part_iter_next

==================================================================
BUG: KASAN: use-after-free in bdev_nr_sectors include/linux/genhd.h:266 [inline]
BUG: KASAN: use-after-free in disk_part_iter_next+0x49d/0x530 block/genhd.c:206
Read of size 8 at addr ffff88801626b9a8 by task syz-executor.0/10146

CPU: 0 PID: 10146 Comm: syz-executor.0 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232
__kasan_report mm/kasan/report.c:399 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
bdev_nr_sectors include/linux/genhd.h:266 [inline]
disk_part_iter_next+0x49d/0x530 block/genhd.c:206
blk_drop_partitions+0x10a/0x180 block/partitions/core.c:543
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1246
__loop_clr_fd+0x7c7/0xff0 drivers/block/loop.c:1271
lo_release+0x1ac/0x1f0 drivers/block/loop.c:1923
__blkdev_put+0x54e/0x800 fs/block_dev.c:1588
blkdev_put+0x92/0x580 fs/block_dev.c:1641
blkdev_close+0x8c/0xb0 fs/block_dev.c:1649
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x41926b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffc4fc09520 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 000000000041926b
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b30620070
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000056c9e0
R13: 000000000056c9e0 R14: 000000000056bf60 R15: 0000000000013222

Allocated by task 10160:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:427 [inline]
__kasan_slab_alloc+0x75/0x90 mm/kasan/common.c:460
kasan_slab_alloc include/linux/kasan.h:223 [inline]
slab_post_alloc_hook mm/slab.h:516 [inline]
slab_alloc_node mm/slub.c:2907 [inline]
slab_alloc mm/slub.c:2915 [inline]
kmem_cache_alloc+0x155/0x370 mm/slub.c:2920
bdev_alloc_inode+0x18/0x80 fs/block_dev.c:795
alloc_inode+0x61/0x230 fs/inode.c:234
new_inode_pseudo fs/inode.c:928 [inline]
new_inode+0x27/0x2f0 fs/inode.c:957
bdev_alloc+0x20/0x2f0 fs/block_dev.c:885
add_partition+0x1ab/0x880 block/partitions/core.c:348
bdev_add_partition+0xb6/0x130 block/partitions/core.c:451
blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43
blkpg_ioctl block/ioctl.c:60 [inline]
blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 13:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
____kasan_slab_free mm/kasan/common.c:360 [inline]
____kasan_slab_free mm/kasan/common.c:325 [inline]
__kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367
kasan_slab_free include/linux/kasan.h:199 [inline]
slab_free_hook mm/slub.c:1562 [inline]
slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600
slab_free mm/slub.c:3161 [inline]
kmem_cache_free+0x8a/0x740 mm/slub.c:3177
i_callback+0x3f/0x70 fs/inode.c:223
rcu_do_batch kernel/rcu/tree.c:2559 [inline]
rcu_core+0x74a/0x12f0 kernel/rcu/tree.c:2794
__do_softirq+0x29b/0x9f6 kernel/softirq.c:345

Last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345
__call_rcu kernel/rcu/tree.c:3039 [inline]
call_rcu+0xb1/0x740 kernel/rcu/tree.c:3114
destroy_inode+0x129/0x1b0 fs/inode.c:289
iput_final fs/inode.c:1654 [inline]
iput.part.0+0x57e/0x810 fs/inode.c:1680
iput+0x58/0x70 fs/inode.c:1670
disk_part_iter_exit block/genhd.c:235 [inline]
disk_part_iter_next+0x9a/0x530 block/genhd.c:202
blk_drop_partitions+0x10a/0x180 block/partitions/core.c:543
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1246
loop_reread_partitions+0x29/0x50 drivers/block/loop.c:655
loop_set_status+0x704/0x1050 drivers/block/loop.c:1418
loop_set_status64 drivers/block/loop.c:1538 [inline]
lo_ioctl+0x4ca/0x1620 drivers/block/loop.c:1706
blkdev_ioctl+0x2a1/0x6d0 block/ioctl.c:583
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88801626b980
which belongs to the cache bdev_cache of size 2792
The buggy address is located 40 bytes inside of
2792-byte region [ffff88801626b980, ffff88801626c468)
The buggy address belongs to the page:
page:ffffea0000589a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16268
head:ffffea0000589a00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff8880101bdb40
raw: 0000000000000000 00000000800b000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88801626b880: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
ffff88801626b900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801626b980: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801626ba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801626ba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit: a5f35387 block: Fix a race between reading and freeing par..
git tree: https://github.com/bvanassche/linux
console output: https://syzkaller.appspot.com/x/log.txt?x=13534e62d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=b5da36c3359b30d1
dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
compiler:

2021-03-22 02:37:36

by Ming Lei

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

On Mon, Mar 22, 2021 at 7:03 AM Bart Van Assche <[email protected]> wrote:
>
> On 3/14/21 4:08 AM, syzbot wrote:
> > syzbot found the following issue on:
> >
> > HEAD commit: 280d542f Merge tag 'drm-fixes-2021-03-05' of git://anongit..
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=15ade5aed00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=952047a9dbff6a6a
> > dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
>
> #syz test: https://github.com/bvanassche/linux a5f35387ebdc

It should be the same issue which was addressed by

aebf5db91705 block: fix use-after-free in disk_part_iter_next

but converting to xarray introduced the issue again.

--
Ming Lei

2021-03-22 04:23:26

by Bart Van Assche

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

On 3/21/21 7:35 PM, Ming Lei wrote:
> On Mon, Mar 22, 2021 at 7:03 AM Bart Van Assche <[email protected]> wrote:
>>
>> On 3/14/21 4:08 AM, syzbot wrote:
>>> syzbot found the following issue on:
>>>
>>> HEAD commit: 280d542f Merge tag 'drm-fixes-2021-03-05' of git://anongit..
>>> git tree: upstream
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=15ade5aed00000
>>> kernel config: https://syzkaller.appspot.com/x/.config?x=952047a9dbff6a6a
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
>>
>> #syz test: https://github.com/bvanassche/linux a5f35387ebdc
>
> It should be the same issue which was addressed by
>
> aebf5db91705 block: fix use-after-free in disk_part_iter_next
>
> but converting to xarray introduced the issue again.

Hi Ming,

Since that patch does not re-apply cleanly, do you want to convert that
patch to the latest kernel version or do you perhaps expect me to do that?

Thanks,

Bart.

2021-03-22 07:19:49

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

I've been running the reproducer on a KASAN enable VM for about
15 minutes now, but haven't been able to reproduce it.

Is there a way to inject this proposed fix into the syzbot queue?

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 1a7558917c47d6..f5d5872b89d57e 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -288,15 +288,12 @@ struct device_type part_type = {
void delete_partition(struct block_device *part)
{
xa_erase(&part->bd_disk->part_tbl, part->bd_partno);
- kobject_put(part->bd_holder_dir);
- device_del(&part->bd_device);
-
- /*
- * Remove the block device from the inode hash, so that it cannot be
- * looked up any more even when openers still hold references.
- */
remove_inode_hash(part->bd_inode);

+ synchronize_rcu();
+
+ kobject_put(part->bd_holder_dir);
+ device_del(&part->bd_device);
put_device(&part->bd_device);
}

2021-03-22 07:51:33

by Dmitry Vyukov

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

On Mon, Mar 22, 2021 at 8:18 AM Christoph Hellwig <[email protected]> wrote:
>
> I've been running the reproducer on a KASAN enable VM for about
> 15 minutes now, but haven't been able to reproduce it.
>
> Is there a way to inject this proposed fix into the syzbot queue?

Hi Christoph,

Yes, since this bug has a reproducer, syzbot can test patches. See:

http://bit.do/syzbot#testing-patches

It would be, for example:

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
master


> diff --git a/block/partitions/core.c b/block/partitions/core.c
> index 1a7558917c47d6..f5d5872b89d57e 100644
> --- a/block/partitions/core.c
> +++ b/block/partitions/core.c
> @@ -288,15 +288,12 @@ struct device_type part_type = {
> void delete_partition(struct block_device *part)
> {
> xa_erase(&part->bd_disk->part_tbl, part->bd_partno);
> - kobject_put(part->bd_holder_dir);
> - device_del(&part->bd_device);
> -
> - /*
> - * Remove the block device from the inode hash, so that it cannot be
> - * looked up any more even when openers still hold references.
> - */
> remove_inode_hash(part->bd_inode);
>
> + synchronize_rcu();
> +
> + kobject_put(part->bd_holder_dir);
> + device_del(&part->bd_device);
> put_device(&part->bd_device);
> }


Attachments:
patch (712.00 B)

2021-03-22 08:02:53

by syzbot

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Read in disk_part_iter_next

==================================================================
BUG: KASAN: use-after-free in bdev_nr_sectors include/linux/genhd.h:266 [inline]
BUG: KASAN: use-after-free in disk_part_iter_next+0x49d/0x530 block/genhd.c:206
Read of size 8 at addr ffff88814403d0a8 by task syz-executor.0/10269

CPU: 1 PID: 10269 Comm: syz-executor.0 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232
__kasan_report mm/kasan/report.c:399 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
bdev_nr_sectors include/linux/genhd.h:266 [inline]
disk_part_iter_next+0x49d/0x530 block/genhd.c:206
partition_overlaps+0x96/0x200 block/partitions/core.c:422
bdev_add_partition+0x66/0x130 block/partitions/core.c:441
blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43
blkpg_ioctl block/ioctl.c:60 [inline]
blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x466459
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f65eb831188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000466459
RDX: 0000000020000240 RSI: 0000000000001269 RDI: 0000000000000003
RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffc7d37ce9f R14: 00007f65eb831300 R15: 0000000000022000

Allocated by task 10226:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:427 [inline]
__kasan_slab_alloc+0x75/0x90 mm/kasan/common.c:460
kasan_slab_alloc include/linux/kasan.h:223 [inline]
slab_post_alloc_hook mm/slab.h:516 [inline]
slab_alloc_node mm/slub.c:2907 [inline]
slab_alloc mm/slub.c:2915 [inline]
kmem_cache_alloc+0x155/0x370 mm/slub.c:2920
bdev_alloc_inode+0x18/0x80 fs/block_dev.c:795
alloc_inode+0x61/0x230 fs/inode.c:234
new_inode_pseudo fs/inode.c:928 [inline]
new_inode+0x27/0x2f0 fs/inode.c:957
bdev_alloc+0x20/0x2f0 fs/block_dev.c:885
add_partition+0x1ab/0x880 block/partitions/core.c:343
bdev_add_partition+0xb6/0x130 block/partitions/core.c:446
blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43
blkpg_ioctl block/ioctl.c:60 [inline]
blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 10255:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
____kasan_slab_free mm/kasan/common.c:360 [inline]
____kasan_slab_free mm/kasan/common.c:325 [inline]
__kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367
kasan_slab_free include/linux/kasan.h:199 [inline]
slab_free_hook mm/slub.c:1562 [inline]
slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600
slab_free mm/slub.c:3161 [inline]
kmem_cache_free+0x8a/0x740 mm/slub.c:3177
i_callback+0x3f/0x70 fs/inode.c:223
rcu_do_batch kernel/rcu/tree.c:2559 [inline]
rcu_core+0x74a/0x12f0 kernel/rcu/tree.c:2794
__do_softirq+0x29b/0x9f6 kernel/softirq.c:345

Last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345
__call_rcu kernel/rcu/tree.c:3039 [inline]
call_rcu+0xb1/0x740 kernel/rcu/tree.c:3114
destroy_inode+0x129/0x1b0 fs/inode.c:289
iput_final fs/inode.c:1654 [inline]
iput.part.0+0x57e/0x810 fs/inode.c:1680
iput+0x58/0x70 fs/inode.c:1670
disk_part_iter_exit block/genhd.c:235 [inline]
disk_part_iter_next+0x9a/0x530 block/genhd.c:202
blk_drop_partitions+0x10a/0x180 block/partitions/core.c:538
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1246
loop_reread_partitions+0x29/0x50 drivers/block/loop.c:655
loop_set_status+0x704/0x1050 drivers/block/loop.c:1418
loop_set_status64 drivers/block/loop.c:1538 [inline]
lo_ioctl+0x4ca/0x1620 drivers/block/loop.c:1706
blkdev_ioctl+0x2a1/0x6d0 block/ioctl.c:583
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88814403d080
which belongs to the cache bdev_cache of size 2792
The buggy address is located 40 bytes inside of
2792-byte region [ffff88814403d080, ffff88814403db68)
The buggy address belongs to the page:
page:ffffea0005100e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x144038
head:ffffea0005100e00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x57ff00000010200(slab|head)
raw: 057ff00000010200 dead000000000100 dead000000000122 ffff8880101bdb40
raw: 0000000000000000 00000000000b000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88814403cf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
ffff88814403d000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88814403d080: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88814403d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88814403d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit: 0d02ec6b Linux 5.12-rc4
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=127b4506d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=4b6433fa3370faed
dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
compiler:
patch: https://syzkaller.appspot.com/x/patch.diff?x=14d738bed00000

2021-03-22 08:55:25

by Ming Lei

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

On Sun, Mar 14, 2021 at 7:10 PM syzbot
<[email protected]> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 280d542f Merge tag 'drm-fixes-2021-03-05' of git://anongit..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15ade5aed00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=952047a9dbff6a6a
> dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]

#syz test: https://github.com/ming1/linux.git v5.12-block-test

2021-03-22 10:12:46

by syzbot

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Read in bdgrab

==================================================================
BUG: KASAN: use-after-free in bdgrab+0x4c/0x50 fs/block_dev.c:938
Read of size 8 at addr ffff88814442d0a8 by task syz-executor.4/10282

CPU: 1 PID: 10282 Comm: syz-executor.4 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232
__kasan_report mm/kasan/report.c:399 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
bdgrab+0x4c/0x50 fs/block_dev.c:938
disk_part_iter_next+0x1ce/0x530 block/genhd.c:206
partition_overlaps+0x96/0x200 block/partitions/core.c:425
bdev_add_partition+0x66/0x130 block/partitions/core.c:444
blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43
blkpg_ioctl block/ioctl.c:60 [inline]
blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x466459
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8adaa92188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000466459
RDX: 0000000020000240 RSI: 0000000000001269 RDI: 0000000000000003
RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffef77424cf R14: 00007f8adaa92300 R15: 0000000000022000

Allocated by task 10147:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:427 [inline]
__kasan_slab_alloc+0x75/0x90 mm/kasan/common.c:460
kasan_slab_alloc include/linux/kasan.h:223 [inline]
slab_post_alloc_hook mm/slab.h:516 [inline]
slab_alloc_node mm/slub.c:2907 [inline]
slab_alloc mm/slub.c:2915 [inline]
kmem_cache_alloc+0x155/0x370 mm/slub.c:2920
bdev_alloc_inode+0x18/0x80 fs/block_dev.c:795
alloc_inode+0x61/0x230 fs/inode.c:234
new_inode_pseudo fs/inode.c:928 [inline]
new_inode+0x27/0x2f0 fs/inode.c:957
bdev_alloc+0x20/0x2f0 fs/block_dev.c:885
add_partition+0x1ab/0x880 block/partitions/core.c:346
bdev_add_partition+0xb6/0x130 block/partitions/core.c:449
blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43
blkpg_ioctl block/ioctl.c:60 [inline]
blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 346:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
____kasan_slab_free mm/kasan/common.c:360 [inline]
____kasan_slab_free mm/kasan/common.c:325 [inline]
__kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367
kasan_slab_free include/linux/kasan.h:199 [inline]
slab_free_hook mm/slub.c:1562 [inline]
slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600
slab_free mm/slub.c:3161 [inline]
kmem_cache_free+0x8a/0x740 mm/slub.c:3177
i_callback+0x3f/0x70 fs/inode.c:223
rcu_do_batch kernel/rcu/tree.c:2559 [inline]
rcu_core+0x74a/0x12f0 kernel/rcu/tree.c:2794
__do_softirq+0x29b/0x9f6 kernel/softirq.c:345

Last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345
__call_rcu kernel/rcu/tree.c:3039 [inline]
call_rcu+0xb1/0x740 kernel/rcu/tree.c:3114
destroy_inode+0x129/0x1b0 fs/inode.c:289
iput_final fs/inode.c:1654 [inline]
iput.part.0+0x57e/0x810 fs/inode.c:1680
iput+0x58/0x70 fs/inode.c:1670
disk_part_iter_exit block/genhd.c:236 [inline]
disk_part_iter_next+0x9b/0x530 block/genhd.c:202
blk_drop_partitions+0x10a/0x180 block/partitions/core.c:541
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1246
loop_reread_partitions+0x29/0x50 drivers/block/loop.c:655
loop_set_status+0x704/0x1050 drivers/block/loop.c:1418
loop_set_status64 drivers/block/loop.c:1538 [inline]
lo_ioctl+0x4ca/0x1620 drivers/block/loop.c:1706
blkdev_ioctl+0x2a1/0x6d0 block/ioctl.c:583
block_ioctl+0xf9/0x140 fs/block_dev.c:1667
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88814442d080
which belongs to the cache bdev_cache of size 2792
The buggy address is located 40 bytes inside of
2792-byte region [ffff88814442d080, ffff88814442db68)
The buggy address belongs to the page:
page:ffffea0005110a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x144428
head:ffffea0005110a00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x57ff00000010200(slab|head)
raw: 057ff00000010200 dead000000000100 dead000000000122 ffff8880101bdb40
raw: 0000000000000000 00000000800b000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88814442cf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
ffff88814442d000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88814442d080: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88814442d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88814442d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit: ee788c30 block: fix use-after-free in disk_part_iter_next
git tree: https://github.com/ming1/linux.git v5.12-block-test
console output: https://syzkaller.appspot.com/x/log.txt?x=15f526d6d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=b5da36c3359b30d1
dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
compiler:

2021-03-22 22:24:54

by Bart Van Assche

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

On 3/22/21 12:18 AM, Christoph Hellwig wrote:
> I've been running the reproducer on a KASAN enable VM for about
> 15 minutes now, but haven't been able to reproduce it.
>
> Is there a way to inject this proposed fix into the syzbot queue?
>
> diff --git a/block/partitions/core.c b/block/partitions/core.c
> index 1a7558917c47d6..f5d5872b89d57e 100644
> --- a/block/partitions/core.c
> +++ b/block/partitions/core.c
> @@ -288,15 +288,12 @@ struct device_type part_type = {
> void delete_partition(struct block_device *part)
> {
> xa_erase(&part->bd_disk->part_tbl, part->bd_partno);
> - kobject_put(part->bd_holder_dir);
> - device_del(&part->bd_device);
> -
> - /*
> - * Remove the block device from the inode hash, so that it cannot be
> - * looked up any more even when openers still hold references.
> - */
> remove_inode_hash(part->bd_inode);
>
> + synchronize_rcu();
> +
> + kobject_put(part->bd_holder_dir);
> + device_del(&part->bd_device);
> put_device(&part->bd_device);
> }

Hi Christoph,

disk_part_iter_next() calls bdgrab() before returning a pointer to a
certain partition. 'part' is only freed if its reference count drops to
zero. The function that frees the partition information,
bdev_free_inode(), is invoked via call_rcu(). bdgrab() fails if the
refcount of a partition is zero. Does that mean that it is not necessary
to call synchronize_rcu() between xa_erase() and put_device()?

Thanks,

Bart.

2021-03-24 11:26:56

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

#syz test: git://git.infradead.org/users/hch/block.git part-iter-fix


On Sun, Mar 21, 2021 at 05:40:05AM -0700, syzbot wrote:
> syzbot has bisected this issue to:
>
> commit a33df75c6328bf40078b35f2040d8e54d574c357
> Author: Christoph Hellwig <[email protected]>
> Date: Sun Jan 24 10:02:41 2021 +0000
>
> block: use an xarray for disk->part_tbl
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17989906d00000
> start commit: 1c273e10 Merge tag 'zonefs-5.12-rc4' of git://git.kernel.o..
> git tree: upstream
> final oops: https://syzkaller.appspot.com/x/report.txt?x=14589906d00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=10589906d00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=6abda3336c698a07
> dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13dfe8bed00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=155a117cd00000
>
> Reported-by: [email protected]
> Fixes: a33df75c6328 ("block: use an xarray for disk->part_tbl")
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
---end quoted text---

2021-03-25 02:43:49

by syzbot

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Read in bdgrab

==================================================================
BUG: KASAN: use-after-free in bdgrab+0x4c/0x50 fs/block_dev.c:929
Read of size 8 at addr ffff88801639a2a8 by task syz-executor.0/10133

CPU: 1 PID: 10133 Comm: syz-executor.0 Not tainted 5.12.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232
__kasan_report mm/kasan/report.c:399 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
bdgrab+0x4c/0x50 fs/block_dev.c:929
first_partition+0xfa/0x230 block/partitions/core.c:538
blk_drop_partitions+0xb5/0xf0 block/partitions/core.c:555
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1237
__loop_clr_fd+0x7c7/0xff0 drivers/block/loop.c:1271
lo_release+0x1ac/0x1f0 drivers/block/loop.c:1923
__blkdev_put+0x54e/0x800 fs/block_dev.c:1579
blkdev_put+0x92/0x580 fs/block_dev.c:1632
blkdev_close+0x8c/0xb0 fs/block_dev.c:1640
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x41926b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007fff13e6a990 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 000000000041926b
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b2fb20070
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000056c9e0
R13: 000000000056c9e0 R14: 000000000056bf60 R15: 000000000001383c

Allocated by task 10136:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:427 [inline]
__kasan_slab_alloc+0x75/0x90 mm/kasan/common.c:460
kasan_slab_alloc include/linux/kasan.h:223 [inline]
slab_post_alloc_hook mm/slab.h:516 [inline]
slab_alloc_node mm/slub.c:2907 [inline]
slab_alloc mm/slub.c:2915 [inline]
kmem_cache_alloc+0x155/0x370 mm/slub.c:2920
bdev_alloc_inode+0x18/0x80 fs/block_dev.c:786
alloc_inode+0x61/0x230 fs/inode.c:234
new_inode_pseudo fs/inode.c:928 [inline]
new_inode+0x27/0x2f0 fs/inode.c:957
bdev_alloc+0x20/0x2f0 fs/block_dev.c:876
add_partition+0x1ab/0x8a0 block/partitions/core.c:348
bdev_add_partition+0xb6/0x130 block/partitions/core.c:451
blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43
blkpg_ioctl block/ioctl.c:60 [inline]
blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548
block_ioctl+0xf9/0x140 fs/block_dev.c:1658
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 4849:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
____kasan_slab_free mm/kasan/common.c:360 [inline]
____kasan_slab_free mm/kasan/common.c:325 [inline]
__kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367
kasan_slab_free include/linux/kasan.h:199 [inline]
slab_free_hook mm/slub.c:1562 [inline]
slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600
slab_free mm/slub.c:3161 [inline]
kmem_cache_free+0x8a/0x740 mm/slub.c:3177
i_callback+0x3f/0x70 fs/inode.c:223
rcu_do_batch kernel/rcu/tree.c:2559 [inline]
rcu_core+0x74a/0x12f0 kernel/rcu/tree.c:2794
__do_softirq+0x29b/0x9f6 kernel/softirq.c:345

Last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345
__call_rcu kernel/rcu/tree.c:3039 [inline]
call_rcu+0xb1/0x740 kernel/rcu/tree.c:3114
destroy_inode+0x129/0x1b0 fs/inode.c:289
iput_final fs/inode.c:1654 [inline]
iput.part.0+0x57e/0x810 fs/inode.c:1680
iput+0x58/0x70 fs/inode.c:1670
blk_drop_partitions+0x9d/0xf0 block/partitions/core.c:557
bdev_disk_changed+0x238/0x430 fs/block_dev.c:1237
loop_reread_partitions+0x29/0x50 drivers/block/loop.c:655
loop_set_status+0x704/0x1050 drivers/block/loop.c:1418
loop_set_status64 drivers/block/loop.c:1538 [inline]
lo_ioctl+0x4ca/0x1620 drivers/block/loop.c:1706
blkdev_ioctl+0x2a1/0x6d0 block/ioctl.c:583
block_ioctl+0xf9/0x140 fs/block_dev.c:1658
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88801639a280
which belongs to the cache bdev_cache of size 2792
The buggy address is located 40 bytes inside of
2792-byte region [ffff88801639a280, ffff88801639ad68)
The buggy address belongs to the page:
page:ffffea000058e600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16398
head:ffffea000058e600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff8880101bdb40
raw: 0000000000000000 00000000800b000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88801639a180: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
ffff88801639a200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801639a280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801639a300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801639a380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit: 7b997e8f block: simplify partition removal
git tree: git://git.infradead.org/users/hch/block.git part-iter-fix
console output: https://syzkaller.appspot.com/x/log.txt?x=14d147aed00000
kernel config: https://syzkaller.appspot.com/x/.config?x=c000f42ea85d0228
dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
compiler:

2021-03-26 08:38:31

by Ming Lei

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

On Sun, Mar 14, 2021 at 7:10 PM syzbot
<[email protected]> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 280d542f Merge tag 'drm-fixes-2021-03-05' of git://anongit..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15ade5aed00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=952047a9dbff6a6a
> dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139

#syz test: https://github.com/ming1/linux.git v5.12-block-test

2021-03-26 17:03:36

by syzbot

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in kvm_wait

------------[ cut here ]------------
raw_local_irq_restore() called with IRQs enabled
WARNING: CPU: 1 PID: 10753 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:10
Modules linked in:
CPU: 1 PID: 10753 Comm: syz-executor.4 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:10
Code: be ff cc cc cc cc cc cc cc cc cc cc cc 80 3d a1 e7 2b 04 00 74 01 c3 48 c7 c7 20 92 6b 89 c6 05 90 e7 2b 04 01 e8 79 cf be ff <0f> 0b c3 48 39 77 10 0f 84 97 00 00 00 66 f7 47 22 f0 ff 74 4b 48
RSP: 0018:ffffc90008f0f9c0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff888021f02040 RCX: 0000000000000000
RDX: ffff888017d4d4c0 RSI: ffffffff815c3875 RDI: fffff520011e1f2a
RBP: 0000000000000200 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815bc60e R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10043e0408 R14: 0000000000000001 R15: ffff8880b9f35f40
FS: 00000000022dd400(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004e4a64 CR3: 0000000016964000 CR4: 0000000000350ee0
Call Trace:
kvm_wait arch/x86/kernel/kvm.c:860 [inline]
kvm_wait+0xc9/0xe0 arch/x86/kernel/kvm.c:837
pv_wait arch/x86/include/asm/paravirt.h:564 [inline]
pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
__pv_queued_spin_lock_slowpath+0x8b8/0xb40 kernel/locking/qspinlock.c:508
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113
spin_lock include/linux/spinlock.h:354 [inline]
ext4_lock_group fs/ext4/ext4.h:3383 [inline]
__ext4_new_inode+0x384f/0x5570 fs/ext4/ialloc.c:1188
ext4_symlink+0x489/0xd50 fs/ext4/namei.c:3347
vfs_symlink fs/namei.c:4176 [inline]
vfs_symlink+0x10f/0x270 fs/namei.c:4161
do_symlinkat+0x27a/0x300 fs/namei.c:4206
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x465d67
Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffda32c3708 EFLAGS: 00000202 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000465d67
RDX: 00007ffda32c37f3 RSI: 00000000004bfab2 RDI: 00007ffda32c37e0
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffda32c35a0
R10: 00007ffda32c3457 R11: 0000000000000202 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffda32c37e0


Tested on:

commit: c47a2e74 block: not create too many partitions
git tree: https://github.com/ming1/linux.git v5.12-block-test
console output: https://syzkaller.appspot.com/x/log.txt?x=11d037e6d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=b5da36c3359b30d1
dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139
compiler:

2021-03-27 06:59:03

by Ming Lei

[permalink] [raw]
Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2)

On Sat, Mar 27, 2021 at 1:01 AM syzbot
<[email protected]> wrote:
>
> Hello,
>
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> WARNING in kvm_wait
>
> ------------[ cut here ]------------
> raw_local_irq_restore() called with IRQs enabled
> WARNING: CPU: 1 PID: 10753 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:10
> Modules linked in:
> CPU: 1 PID: 10753 Comm: syz-executor.4 Not tainted 5.12.0-rc3-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:10
> Code: be ff cc cc cc cc cc cc cc cc cc cc cc 80 3d a1 e7 2b 04 00 74 01 c3 48 c7 c7 20 92 6b 89 c6 05 90 e7 2b 04 01 e8 79 cf be ff <0f> 0b c3 48 39 77 10 0f 84 97 00 00 00 66 f7 47 22 f0 ff 74 4b 48
> RSP: 0018:ffffc90008f0f9c0 EFLAGS: 00010286
> RAX: 0000000000000000 RBX: ffff888021f02040 RCX: 0000000000000000
> RDX: ffff888017d4d4c0 RSI: ffffffff815c3875 RDI: fffff520011e1f2a
> RBP: 0000000000000200 R08: 0000000000000000 R09: 0000000000000000
> R10: ffffffff815bc60e R11: 0000000000000000 R12: 0000000000000003
> R13: ffffed10043e0408 R14: 0000000000000001 R15: ffff8880b9f35f40
> FS: 00000000022dd400(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00000000004e4a64 CR3: 0000000016964000 CR4: 0000000000350ee0
> Call Trace:
> kvm_wait arch/x86/kernel/kvm.c:860 [inline]
> kvm_wait+0xc9/0xe0 arch/x86/kernel/kvm.c:837
> pv_wait arch/x86/include/asm/paravirt.h:564 [inline]
> pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
> __pv_queued_spin_lock_slowpath+0x8b8/0xb40 kernel/locking/qspinlock.c:508
> pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline]
> queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
> queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
> do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113
> spin_lock include/linux/spinlock.h:354 [inline]
> ext4_lock_group fs/ext4/ext4.h:3383 [inline]
> __ext4_new_inode+0x384f/0x5570 fs/ext4/ialloc.c:1188
> ext4_symlink+0x489/0xd50 fs/ext4/namei.c:3347
> vfs_symlink fs/namei.c:4176 [inline]
> vfs_symlink+0x10f/0x270 fs/namei.c:4161
> do_symlinkat+0x27a/0x300 fs/namei.c:4206
> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
> entry_SYSCALL_64_after_hwframe+0x44/0xae
> RIP: 0033:0x465d67
> Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffda32c3708 EFLAGS: 00000202 ORIG_RAX: 0000000000000058
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000465d67
> RDX: 00007ffda32c37f3 RSI: 00000000004bfab2 RDI: 00007ffda32c37e0
> RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffda32c35a0
> R10: 00007ffda32c3457 R11: 0000000000000202 R12: 0000000000000001
> R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffda32c37e0

This is another & un-related warning with original report, so I think
the patch in above
tree fixes the issue.


--
Ming Lei