Hi,
syzbot find a bug[0] in ext4 on android13-5.15-lts as below and it can
be reproduced on mailine v6.1-rc5(094226ad94f4) too The log from
mainline can be found in URL [1]. The bisect test shows below
commit[2] is the first commit that reproduce the bug. With reverting
the commit, there is no bug reproduced[3].
Is reverting the commit 21175ca434c5 a acceptable solution? Any fix
work is in progress?
[0] https://syzkaller.appspot.com/bug?id=5bafe4554067100b70f58a81268aa06ea3f9c345
[1] https://syzkaller.appspot.com/text?tag=CrashLog&x=118359c1880000
[2] 21175ca434c5 ext4: make prefetch_block_bitmaps default
[3] https://groups.google.com/g/syzkaller-android-bugs/c/HKLNVJQICMM/m/YcHNpH_iBAAJ
kernel BUG at fs/ext4/inline.c:227!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Call Trace:
<TASK>
ext4_write_end+0x1af/0x9d0 fs/ext4/inode.c:1307
ext4_da_write_end+0x92/0xa70 fs/ext4/inode.c:3067
generic_perform_write+0x3c7/0x5d0 mm/filemap.c:3836
ext4_buffered_write_iter+0x49b/0x630 fs/ext4/file.c:271
ext4_file_write_iter+0x456/0x1dc0
do_iter_readv_writev+0x52a/0x720
do_iter_write+0x1f4/0x760 fs/read_write.c:855
vfs_iter_write+0x7c/0xa0 fs/read_write.c:896
iter_file_splice_write+0x810/0xfd0 fs/splice.c:689
do_splice_from fs/splice.c:767 [inline]
direct_splice_actor+0xfe/0x130 fs/splice.c:934
splice_direct_to_actor+0x4d4/0xbd0 fs/splice.c:889
do_splice_direct+0x2a0/0x3f0 fs/splice.c:977
do_sendfile+0x63b/0xfd0 fs/read_write.c:1249
__do_sys_sendfile64 fs/read_write.c:1317 [inline]
__se_sys_sendfile64 fs/read_write.c:1303 [inline]
__x64_sys_sendfile64+0x1ce/0x230 fs/read_write.c:1303
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb
Regards,
Jun
Hi,
syzbot find a new bug[1] in ext4 that's similar with bug[0], that
leads to reboot.
While the bug[0] can be fixed with patch[2] from Bin. This new bug is still
triggered with the patch[2], and log[3] is collected. Both log[1] and
log[3] are
collected when testing bug[4] on the mainline.
[0] https://syzkaller.appspot.com/bug?id=5bafe4554067100b70f58a81268aa06ea3f9c345
[1] https://syzkaller.appspot.com/text?tag=CrashLog&x=16325fc3880000
[2] https://lore.kernel.org/lkml/CABymUCN+NSzkunRqFs8LgqjT6vXz-gyyZYn0hQWf8V9kmcO0Hw@mail.gmail.com/T/
[3] https://syzkaller.appspot.com/text?tag=CrashLog&x=155abe7b880000
[4] https://syzkaller.appspot.com/bug?id=899b37f20ce4072bcdfecfe1647b39602e956e36
[ 38.932317][ T494] Call Trace:
[ 38.935437][ T494] <TASK>
[ 38.938393][ T494] ext4_write_inline_data_end+0xa39/0xdf0
[ 38.943946][ T494] ? put_page+0xa0/0xa0
[ 38.947936][ T494] ? ext4_da_write_begin+0x6f0/0x8d0
[ 38.953055][ T494] ? pipe_zero+0x240/0x240
[ 38.957308][ T494] ext4_da_write_end+0x1e2/0x950
[ 38.962082][ T494] ? ext4_da_write_begin+0x8d0/0x8d0
[ 38.967204][ T494] generic_perform_write+0x401/0x5f0
[ 38.972326][ T494] ? generic_file_direct_write+0x6c0/0x6c0
[ 38.977994][ T494] ? generic_write_checks_count+0x4b0/0x4b0
[ 38.983694][ T494] ext4_buffered_write_iter+0x35f/0x640
[ 38.989074][ T494] ext4_file_write_iter+0x198/0x1cd0
[ 38.994194][ T494] ? futex_unqueue+0x156/0x180
[ 38.998795][ T494] ? futex_wait+0x4c5/0x5c0
[ 39.003307][ T494] ? futex_wait_setup+0x320/0x320
[ 39.008168][ T494] ? avc_policy_seqno+0x1b/0x70
[ 39.012862][ T494] ? ext4_file_read_iter+0x470/0x470
[ 39.017976][ T494] vfs_write+0x8b5/0xef0
[ 39.022056][ T494] ? file_end_write+0x1b0/0x1b0
[ 39.026739][ T494] ? mutex_lock+0xb6/0x130
[ 39.030994][ T494] ? bit_wait_io_timeout+0x110/0x110
[ 39.036117][ T494] ? __fget_files+0x2d9/0x330
[ 39.040630][ T494] ? __fdget_pos+0x268/0x300
[ 39.045054][ T494] ? ksys_write+0x77/0x2c0
[ 39.049307][ T494] ksys_write+0x198/0x2c0
[ 39.053472][ T494] ? save_fpregs_to_fpstate+0x210/0x210
[ 39.058855][ T494] ? __ia32_sys_read+0x90/0x90
[ 39.063465][ T494] ? __kasan_check_write+0x14/0x20
[ 39.068403][ T494] ? switch_fpu_return+0x129/0x270
[ 39.073348][ T494] __x64_sys_write+0x7b/0x90
[ 39.077783][ T494] do_syscall_64+0x2f/0x50
[ 39.082030][ T494] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Regards,
Jun