Hi printk maintainers,
I've got the following out-of-bounds in printk code.
This is on next-20200925. Config is attached.
This is just on pr_cont("\n"). Something overreads the string.
==================================================================
BUG: KASAN: global-out-of-bounds in memchr+0x65/0x80 lib/string.c:1058
Read of size 1 at addr ffffffff8c68c860 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc6-next-20200925+ #43
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x14b/0x18f lib/dump_stack.c:118
print_address_description.constprop.0.cold+0x5/0x4c5 mm/kasan/report.c:385
__kasan_report mm/kasan/report.c:545 [inline]
kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
memchr+0x65/0x80 lib/string.c:1058
memchr include/linux/string.h:450 [inline]
record_print_text+0x22d/0x310 kernel/printk/printk.c:1369
console_unlock+0x350/0xbc0 kernel/printk/printk.c:2477
vprintk_emit+0x348/0x4b0 kernel/printk/printk.c:2021
vprintk_func+0x8d/0x1e0 kernel/printk/printk_safe.c:393
printk+0xba/0xed kernel/printk/printk.c:2069
show_pwq+0x74d/0x7ee kernel/workqueue.c:4745
show_workqueue_state.cold+0xd0/0x3c9 kernel/workqueue.c:4784
wq_watchdog_timer_fn+0x2e5/0x370 kernel/workqueue.c:5798
call_timer_fn+0x38/0x2d0 kernel/time/timer.c:1413
expire_timers kernel/time/timer.c:1458 [inline]
__run_timers kernel/time/timer.c:1755 [inline]
__run_timers kernel/time/timer.c:1731 [inline]
run_timer_softirq+0xad2/0x1440 kernel/time/timer.c:1770
__do_softirq+0x1f0/0x6c4 kernel/softirq.c:298
asm_call_irq_on_stack+0xf/0x20
</IRQ>
__run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
do_softirq_own_stack+0x58/0x70 arch/x86/kernel/irq_64.c:77
invoke_softirq kernel/softirq.c:393 [inline]
__irq_exit_rcu kernel/softirq.c:423 [inline]
irq_exit_rcu+0x137/0x170 kernel/softirq.c:435
sysvec_apic_timer_interrupt+0x34/0xb0 arch/x86/kernel/apic/apic.c:1091
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: ff cc cc cc cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d b4
9f 5e 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d a4 9f 5e 00 fb f4 <c3> cc
41 54 55 53 e8 57 b5 fd ff 0f 1f 44 00 00 e8 ed 88 72 f9 48
RSP: 0018:ffffffff89a07e20 EFLAGS: 00000282
RAX: 1ffffffff136c688 RBX: ffffffff89a3bc40 RCX: ffffffff87e7dae8
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffed100dd469e9
R10: ffff88806ea34f43 R11: ffffed100dd469e8 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8b15e748 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline]
default_idle+0x2a/0x40 arch/x86/kernel/process.c:688
default_idle_call+0x9c/0x280 kernel/sched/idle.c:98
cpuidle_idle_call kernel/sched/idle.c:168 [inline]
do_idle+0x3b5/0x690 kernel/sched/idle.c:273
cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:369
start_kernel+0x435/0x456 init/main.c:1049
secondary_startup_64_no_verify+0xa6/0xab
The buggy address belongs to the variable:
text.49461+0x400/0x420
Memory state around the buggy address:
ffffffff8c68c700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffffff8c68c780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffff8c68c800: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9
^
ffffffff8c68c880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffffff8c68c900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Cc-ing John and Steven
On (20/09/27 11:12), Dmitry Vyukov wrote:
> Hi printk maintainers,
>
> I've got the following out-of-bounds in printk code.
> This is on next-20200925. Config is attached.
> This is just on pr_cont("\n"). Something overreads the string.
>
> ==================================================================
> BUG: KASAN: global-out-of-bounds in memchr+0x65/0x80 lib/string.c:1058
> Read of size 1 at addr ffffffff8c68c860 by task swapper/0/0
Thanks for the report. I think this should be fixed by
https://lore.kernel.org/lkml/[email protected]/
-ss
On Sun, Sep 27, 2020 at 11:12:23AM +0200, Dmitry Vyukov wrote:
> Hi printk maintainers,
>
> I've got the following out-of-bounds in printk code.
> This is on next-20200925. Config is attached.
> This is just on pr_cont("\n"). Something overreads the string.
>
> ==================================================================
> BUG: KASAN: global-out-of-bounds in memchr+0x65/0x80 lib/string.c:1058
> Read of size 1 at addr ffffffff8c68c860 by task swapper/0/0
Would be helpful to show the text before this, so we have a better idea of
where it happened.
-- Steve
>
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc6-next-20200925+ #43
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
> Call Trace:
> <IRQ>
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x14b/0x18f lib/dump_stack.c:118
> print_address_description.constprop.0.cold+0x5/0x4c5 mm/kasan/report.c:385
> __kasan_report mm/kasan/report.c:545 [inline]
> kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
> memchr+0x65/0x80 lib/string.c:1058
> memchr include/linux/string.h:450 [inline]
> record_print_text+0x22d/0x310 kernel/printk/printk.c:1369
> console_unlock+0x350/0xbc0 kernel/printk/printk.c:2477
> vprintk_emit+0x348/0x4b0 kernel/printk/printk.c:2021
> vprintk_func+0x8d/0x1e0 kernel/printk/printk_safe.c:393
> printk+0xba/0xed kernel/printk/printk.c:2069
> show_pwq+0x74d/0x7ee kernel/workqueue.c:4745
> show_workqueue_state.cold+0xd0/0x3c9 kernel/workqueue.c:4784
> wq_watchdog_timer_fn+0x2e5/0x370 kernel/workqueue.c:5798
> call_timer_fn+0x38/0x2d0 kernel/time/timer.c:1413
> expire_timers kernel/time/timer.c:1458 [inline]
> __run_timers kernel/time/timer.c:1755 [inline]
> __run_timers kernel/time/timer.c:1731 [inline]
> run_timer_softirq+0xad2/0x1440 kernel/time/timer.c:1770
> __do_softirq+0x1f0/0x6c4 kernel/softirq.c:298
> asm_call_irq_on_stack+0xf/0x20
On Mon, Sep 28, 2020 at 5:19 PM Steven Rostedt <[email protected]> wrote:
>
> On Sun, Sep 27, 2020 at 11:12:23AM +0200, Dmitry Vyukov wrote:
> > Hi printk maintainers,
> >
> > I've got the following out-of-bounds in printk code.
> > This is on next-20200925. Config is attached.
> > This is just on pr_cont("\n"). Something overreads the string.
> >
> > ==================================================================
> > BUG: KASAN: global-out-of-bounds in memchr+0x65/0x80 lib/string.c:1058
> > Read of size 1 at addr ffffffff8c68c860 by task swapper/0/0
>
> Would be helpful to show the text before this, so we have a better idea of
> where it happened.
Here is full output:
[ 923.904916][ C2] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[ 923.908851][ C2] rcu: 1-...0: (1 GPs behind)
idle=c9a/1/0x4000000000000000 softirq=65097/65098 fqs=5000
[ 923.910258][ C2] (detected by 2, t=10002 jiffies, g=79113, q=1645)
[ 923.910273][ C2] Sending NMI from CPU 2 to CPUs 1:
[ 923.912954][ C2] NMI backtrace for cpu 1
[ 923.912960][ C2] CPU: 1 PID: 24557 Comm: getty Not tainted
5.9.0-rc5-next-20200916 #36
[ 923.912966][ C2] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS 1.13.0-1 04/01/2014
[ 923.912971][ C2] RIP: 0010:check_memory_region+0x16/0x1b0
[ 923.912983][ C2] Code: 01 0f 1f 00 48 89 f2 be f8 00 00 00 e9 63
3c f4 01 0f 1f 00 48 85 f6 0f 84 53 01 00 00 49 89 fa 41 54 0f b6 d2
49 01 f2 55 53 <0f> 82 2d 01 00 00 48 b8 ff ff ff ff ff 7f ff ff 48 39
c7 0f 86 1a
[ 923.912988][ C2] RSP: 0018:ffffc90000170db8 EFLAGS: 00000086
[ 923.913012][ C2] RAX: dffffc0000000000 RBX: ffff88802bb4ca58
RCX: ffffffff862b781d
[ 923.913017][ C2] RDX: 0000000000000000 RSI: 0000000000000008
RDI: ffff88802bb4ca20
[ 923.913023][ C2] RBP: ffff88802bb4ca20 R08: ffff88803b44a680
R09: fffff5200002e1ae
[ 923.913028][ C2] R10: ffff88802bb4ca28 R11: fffff5200002e1ad
R12: ffff8880412f8f00
[ 923.913034][ C2] R13: 1b8d2fad371a5f5a R14: 0000000000000000
R15: 1b8d2fad371a5f5a
[ 923.913039][ C2] FS: 00007fa3bed78700(0000)
GS:ffff88806ea80000(0000) knlGS:0000000000000000
[ 923.913043][ C2] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 923.913048][ C2] CR2: 00007f5f11a2df18 CR3: 000000001c78b001
CR4: 0000000000770ee0
[ 923.913053][ C2] DR0: 0000000000000000 DR1: 0000000000000000
DR2: 0000000000000000
[ 923.913057][ C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0
DR7: 0000000000000400
[ 923.913060][ C2] PKRU: 55555554
[ 923.913064][ C2] Call Trace:
[ 923.913066][ C2] <IRQ>
[ 923.913069][ C2] advance_sched+0x2ed/0x6d0
[ 923.913073][ C2] ? taprio_enqueue+0x1090/0x1090
[ 923.913077][ C2] __hrtimer_run_queues+0x331/0x820
[ 923.913081][ C2] ? enqueue_hrtimer+0x250/0x250
[ 923.913085][ C2] ? ktime_get_update_offsets_now+0x1d8/0x280
[ 923.913089][ C2] hrtimer_interrupt+0x31c/0x790
[ 923.913093][ C2] __sysvec_apic_timer_interrupt+0x10d/0x390
[ 923.913096][ C2] asm_call_on_stack+0xf/0x20
[ 923.913099][ C2] </IRQ>
[ 923.913103][ C2] sysvec_apic_timer_interrupt+0x9a/0xb0
[ 923.913108][ C2] asm_sysvec_apic_timer_interrupt+0x12/0x20
[ 923.913111][ C2] RIP: 0010:rw_verify_area+0x128/0x340
[ 923.913121][ C2] Code: 6e 4c b7 ff 41 83 e4 02 48 89 ef 41 83 c4
02 44 89 e6 e8 bb cd 8c 01 41 89 c4 e8 53 4c b7 ff 44 89 e0 5b 5d 41
5c 41 5d 41 5e <41> 5f c3 e8 40 4c b7 ff 48 8d 7d 5c 48 b8 00 00 00 00
00 fc ff df
[ 923.913127][ C2] RSP: 0018:ffffc9000120fe58 EFLAGS: 00000293
[ 923.913134][ C2] RAX: 0000000000000000 RBX: ffff888031dc5c40
RCX: ffffffff81c7fbb1
[ 923.913140][ C2] RDX: 0000000000000000 RSI: ffffffff81b6610d
RDI: 0000000000000005
[ 923.913146][ C2] RBP: 0000000000000001 R08: ffff88803b44a680
R09: ffffed1002376dd9
[ 923.913151][ C2] R10: ffffc9000120fdf0 R11: ffffed1002376dd8
R12: 00007fffcaf7db99
[ 923.913156][ C2] R13: ffffc9000120fed0 R14: ffff888031dc5c9c
R15: 0000000000000001
[ 923.913159][ C2] ? __fsnotify_parent+0x641/0xa70
[ 923.913164][ C2] ? rw_verify_area+0x11d/0x340
[ 923.913168][ C2] vfs_read+0x120/0x560
[ 923.913171][ C2] ksys_read+0x127/0x250
[ 923.913175][ C2] ? vfs_write+0x700/0x700
[ 923.913180][ C2] ? fpregs_assert_state_consistent+0xbc/0xe0
[ 923.913185][ C2] ? exit_to_user_mode_prepare+0x34/0x160
[ 923.913189][ C2] do_syscall_64+0x2d/0x70
[ 923.913193][ C2] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 923.913198][ C2] RIP: 0033:0x7fa3be6a3310
[ 923.913210][ C2] Code: 73 01 c3 48 8b 0d 28 4b 2b 00 31 d2 48 29
c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d e5 a2 2b 00 00 75 10 b8 00
00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 6e 8a 01 00
48 89 04 24
[ 923.913214][ C2] RSP: 002b:00007fffcaf7db48 EFLAGS: 00000246
ORIG_RAX: 0000000000000000
[ 923.913224][ C2] RAX: ffffffffffffffda RBX: 00007fa3bed786a8
RCX: 00007fa3be6a3310
[ 923.913230][ C2] RDX: 0000000000000001 RSI: 00007fffcaf7db98
RDI: 0000000000000000
[ 923.913235][ C2] RBP: 00007fffcaf7e380 R08: 00000000000000bb
R09: 00007fa3be959e90
[ 923.913240][ C2] R10: 0000000000000000 R11: 0000000000000246
R12: 00000000006075a0
[ 923.913245][ C2] R13: 00007fffcaf81f46 R14: 0000000000000000
R15: 0000000000000000
[ 927.904983][ T12] Bluetooth: hci5: command 0x041b tx timeout
[ 927.907990][ C0] BUG: workqueue lockup - pool cpus=0-3 flags=0x4
nice=0 stuck for 103s!
[ 927.909030][ C0] Showing busy workqueues and worker pools:
[ 927.909946][ C0] workqueue events: flags=0x0
[ 927.910513][ C0] pwq 6: cpus=3 node=0 flags=0x0 nice=0
active=2/256 refcnt=3
[ 927.911590][ C0] in-flight: 8599:xfrm_state_gc_task xfrm_state_gc_task
[ 927.912639][ C0] pwq 4: cpus=2 node=0 flags=0x0 nice=0
active=2/256 refcnt=3
[ 927.913810][ C0] pending: cache_reap, macvlan_process_broadcast
[ 927.914780][ C0] pwq 2: cpus=1 node=0 flags=0x0 nice=0
active=11/256 refcnt=12
[ 927.916019][ C0] pending: nsim_dev_trap_report_work,
nsim_dev_trap_report_work, nsim_dev_trap_report_work,
ovs_dp_masks_rebalance, ovs_dp_masks_rebalance,
ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, psi_avgs_work,
psi_avgs_work, check_corruption, cache_reap
[ 927.919876][ C0] pwq 0: cpus=0 node=0 flags=0x0 nice=0
active=4/256 refcnt=5
[ 927.920369][ T8592] GRED: Unable to relocate VQ 0x0 after dequeue,
screwing up backlog
[ 927.920940][ C0] pending: cache_reap,
ovs_dp_masks_rebalance, switchdev_deferred_process_work,
key_garbage_collector
[ 927.922233][ T17] GRED: Unable to relocate VQ 0x0 after dequeue,
screwing up backlog
[ 927.924007][ C0] workqueue events_long: flags=0x0
[ 927.926021][ C0] pwq 0: cpus=0 node=0 flags=0x0 nice=0
active=1/256 refcnt=2
[ 927.927067][ C0] pending: br_multicast_gc_work
[ 927.928241][ C0] workqueue events_unbound: flags=0x2
[ 927.929390][ C0] pwq 8: cpus=0-3 flags=0x4 nice=0 active=6/512 refcnt=8
[ 927.932368][ C0] pending: io_ring_exit_work,
io_ring_exit_work, io_ring_exit_work, io_ring_exit_work,
fsnotify_connector_destroy_workfn, fsnotify_mark_destroy_workfn
[ 927.936923][ C0] workqueue writeback: flags=0x4a
[ 927.939002][ C0] pwq 8: cpus=0-3 flags=0x4 nice=0 active=8/256 refcnt=10
[ 927.940685][ C0] in-flight: 2590:wb_workfn
[ 927.941693][ C0] pending: wb_workfn, wb_workfn, wb_workfn,
wb_workfn, wb_workfn, wb_workfn, wb_workfn
[ 927.943712][ C0] workqueue krxrpcd: flags=0x0
[ 927.944568][ C0] pwq 0: cpus=0 node=0 flags=0x0 nice=0
active=1/1 refcnt=4
[ 927.946044][ C0] pending: rxrpc_peer_keepalive_worker
[ 927.947217][ C0] delayed: rxrpc_peer_keepalive_worker,
rxrpc_peer_keepalive_worker
[ 927.948953][ C0] workqueue bat_events: flags=0xe000a
[ 927.949807][ C0] pwq 8: cpus=0-3 flags=0x4 nice=0 active=1/1 refcnt=73
[ 927.950953][ C0] in-flight:
275:batadv_iv_send_outstanding_bat_ogm_packet
[ 927.953941][ C0]
==================================================================
[ 927.953948][ C0] BUG: KASAN: global-out-of-bounds in memchr+0x65/0x80
[ 927.953953][ C0] Read of size 1 at addr ffffffff8cb11b60 by task
ksoftirqd/0/9
[ 927.953955][ C0]
[ 927.953961][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted
5.9.0-rc5-next-20200916 #36
[ 927.953967][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS 1.13.0-1 04/01/2014
[ 927.953970][ C0] Call Trace:
[ 927.953973][ C0] dump_stack+0x14b/0x18f
[ 927.953977][ C0] ? memchr+0x65/0x80
[ 927.953980][ C0] ? memchr+0x65/0x80
[ 927.953985][ C0] print_address_description.constprop.0.cold+0x5/0x4c5
[ 927.953989][ C0] ? rwlock_bug.part.0+0x90/0x90
[ 927.953992][ C0] ? desc_read+0x1a5/0x230
[ 927.953996][ C0] ? vprintk_func+0xfd/0x1e0
[ 927.953999][ C0] ? memchr+0x65/0x80
[ 927.954001][ C0] ? memchr+0x65/0x80
[ 927.954005][ C0] kasan_report.cold+0x1f/0x37
[ 927.954008][ C0] ? memchr+0x65/0x80
[ 927.954011][ C0] memchr+0x65/0x80
[ 927.954015][ C0] record_print_text+0x22d/0x310
[ 927.954019][ C0] ? get_record_print_text_size+0x110/0x110
[ 927.954023][ C0] ? prb_read_valid+0x75/0xa0
[ 927.954026][ C0] ? prb_final_commit+0x20/0x20
[ 927.954030][ C0] console_unlock+0x374/0xc20
[ 927.954034][ C0] ? devkmsg_read+0x940/0x940
[ 927.954037][ C0] ? do_raw_spin_lock+0x120/0x2d0
[ 927.954041][ C0] ? do_raw_spin_unlock+0x171/0x260
[ 927.954045][ C0] ? _raw_spin_unlock_irqrestore+0x42/0x70
[ 927.954049][ C0] vprintk_emit+0x352/0x4c0
[ 927.954052][ C0] vprintk_func+0x8d/0x1e0
[ 927.954055][ C0] printk+0xba/0xed
[ 927.954059][ C0] ? record_print_text.cold+0x16/0x16
[ 927.954064][ C0] ? __batadv_dat_purge.isra.0.part.0+0x3d0/0x3d0
[ 927.954067][ C0] ? show_pwq+0x738/0x7e5
[ 927.954070][ C0] ? show_pwq+0x70c/0x7e5
[ 927.954073][ C0] show_pwq+0x744/0x7e5
[ 927.954077][ C0] show_workqueue_state.cold+0xd0/0x3c0
[ 927.954080][ C0] ? print_worker_info+0x280/0x280
[ 927.954084][ C0] ? idr_get_next_ul+0x2a0/0x2a0
[ 927.954088][ C0] ? _raw_spin_unlock_irqrestore+0x42/0x70
[ 927.954092][ C0] wq_watchdog_timer_fn+0x2dc/0x370
[ 927.954096][ C0] ? show_workqueue_state+0x2f0/0x2f0
[ 927.954099][ C0] ? do_raw_spin_lock+0x120/0x2d0
[ 927.954103][ C0] ? show_workqueue_state+0x2f0/0x2f0
[ 927.954107][ C0] ? show_workqueue_state+0x2f0/0x2f0
[ 927.954111][ C0] call_timer_fn+0x38/0x2d0
[ 927.954115][ C0] ? show_workqueue_state+0x2f0/0x2f0
[ 927.954119][ C0] run_timer_softirq+0xad2/0x1440
[ 927.954124][ C0] ? trace_event_raw_event_hrtimer_start+0x350/0x350
[ 927.954128][ C0] ? kvm_clock_read+0x14/0x30
[ 927.954132][ C0] ? kvm_sched_clock_read+0x5/0x10
[ 927.954135][ C0] ? sched_clock+0x2a/0x40
[ 927.954139][ C0] ? sched_clock_cpu+0x18/0x1f0
[ 927.954143][ C0] ? tasklet_action+0x70/0x70
[ 927.954147][ C0] __do_softirq+0x1f0/0x6c4
[ 927.954151][ C0] ? tasklet_action+0x70/0x70
[ 927.954155][ C0] run_ksoftirqd+0x7f/0x100
[ 927.954159][ C0] smpboot_thread_fn+0x655/0x9e0
[ 927.954163][ C0] ? smpboot_register_percpu_thread+0x380/0x380
[ 927.954168][ C0] ? __kthread_parkme+0x13f/0x1e0
[ 927.954173][ C0] ? smpboot_register_percpu_thread+0x380/0x380
[ 927.954176][ C0] kthread+0x3ac/0x490
[ 927.954180][ C0] ? kthread_bind+0x50/0x50
[ 927.954183][ C0] ret_from_fork+0x1f/0x30
[ 927.954185][ C0]
[ 927.954190][ C0] The buggy address belongs to the variable:
[ 927.954193][ C0] text.49533+0x400/0x420
[ 927.954196][ C0]
[ 927.954200][ C0] Memory state around the buggy address:
[ 927.954205][ C0] ffffffff8cb11a00: 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00
[ 927.954211][ C0] ffffffff8cb11a80: 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00
[ 927.954216][ C0] >ffffffff8cb11b00: 00 00 00 00 00 00 00 00 00
00 00 00 f9 f9 f9 f9
[ 927.954221][ C0] ^
[ 927.954227][ C0] ffffffff8cb11b80: 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00
[ 927.954232][ C0] ffffffff8cb11c00: 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00
[ 927.954238][ C0]
==================================================================
[ 927.954242][ C0] Disabling lock debugging due to kernel taint
[ 927.954247][ C0] Kernel panic - not syncing: panic_on_warn set ...
[ 927.954253][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Tainted: G B
5.9.0-rc5-next-20200916 #36
[ 927.954259][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS 1.13.0-1 04/01/2014
[ 927.954262][ C0] Call Trace:
[ 927.954266][ C0] dump_stack+0x14b/0x18f
[ 927.954269][ C0] ? memchr+0x10/0x80
[ 927.954272][ C0] panic+0x319/0x765
[ 927.954276][ C0] ? print_oops_end_marker.cold+0x15/0x15
[ 927.954279][ C0] ? memchr+0x65/0x80
[ 927.954282][ C0] ? memchr+0x65/0x80
[ 927.954286][ C0] end_report+0x58/0x5e
[ 927.954289][ C0] kasan_report.cold+0xd/0x37
[ 927.954292][ C0] ? memchr+0x65/0x80
[ 927.954296][ C0] memchr+0x65/0x80
[ 927.954299][ C0] record_print_text+0x22d/0x310
[ 927.954303][ C0] ? get_record_print_text_size+0x110/0x110
[ 927.954307][ C0] ? prb_read_valid+0x75/0xa0
[ 927.954311][ C0] ? prb_final_commit+0x20/0x20
[ 927.954314][ C0] console_unlock+0x374/0xc20
[ 927.954318][ C0] ? devkmsg_read+0x940/0x940
[ 927.954322][ C0] ? do_raw_spin_lock+0x120/0x2d0
[ 927.954326][ C0] ? do_raw_spin_unlock+0x171/0x260
[ 927.954330][ C0] ? _raw_spin_unlock_irqrestore+0x42/0x70
[ 927.954334][ C0] vprintk_emit+0x352/0x4c0
[ 927.954337][ C0] vprintk_func+0x8d/0x1e0
[ 927.954340][ C0] printk+0xba/0xed
[ 927.954344][ C0] ? record_print_text.cold+0x16/0x16
[ 927.954349][ C0] ? __batadv_dat_purge.isra.0.part.0+0x3d0/0x3d0
[ 927.954352][ C0] ? show_pwq+0x738/0x7e5
[ 927.954356][ C0] ? show_pwq+0x70c/0x7e5
[ 927.954359][ C0] show_pwq+0x744/0x7e5
[ 927.954363][ C0] show_workqueue_state.cold+0xd0/0x3c0
[ 927.954367][ C0] ? print_worker_info+0x280/0x280
[ 927.954370][ C0] ? idr_get_next_ul+0x2a0/0x2a0
[ 927.954375][ C0] ? _raw_spin_unlock_irqrestore+0x42/0x70
[ 927.954379][ C0] wq_watchdog_timer_fn+0x2dc/0x370
[ 927.954383][ C0] ? show_workqueue_state+0x2f0/0x2f0
[ 927.954387][ C0] ? do_raw_spin_lock+0x120/0x2d0
[ 927.954391][ C0] ? show_workqueue_state+0x2f0/0x2f0
[ 927.954394][ C0] ? show_workqueue_state+0x2f0/0x2f0
[ 927.954398][ C0] call_timer_fn+0x38/0x2d0
[ 927.954402][ C0] ? show_workqueue_state+0x2f0/0x2f0
[ 927.954406][ C0] run_timer_softirq+0xad2/0x1440
[ 927.954411][ C0] ? trace_event_raw_event_hrtimer_start+0x350/0x350
[ 927.954415][ C0] ? kvm_clock_read+0x14/0x30
[ 927.954418][ C0] ? kvm_sched_clock_read+0x5/0x10
[ 927.954422][ C0] ? sched_clock+0x2a/0x40
[ 927.954426][ C0] ? sched_clock_cpu+0x18/0x1f0
[ 927.954430][ C0] ? tasklet_action+0x70/0x70
[ 927.954433][ C0] __do_softirq+0x1f0/0x6c4
[ 927.954437][ C0] ? tasklet_action+0x70/0x70
[ 927.954440][ C0] run_ksoftirqd+0x7f/0x100
[ 927.954444][ C0] smpboot_thread_fn+0x655/0x9e0
[ 927.954449][ C0] ? smpboot_register_percpu_thread+0x380/0x380
[ 927.954453][ C0] ? __kthread_parkme+0x13f/0x1e0
[ 927.954457][ C0] ? smpboot_register_percpu_thread+0x380/0x380
[ 927.954460][ C0] kthread+0x3ac/0x490
[ 927.954464][ C0] ? kthread_bind+0x50/0x50
[ 927.954468][ C0] ret_from_fork+0x1f/0x30
[ 927.954472][ C0] Dumping ftrace buffer:
[ 927.954475][ C0] (ftrace buffer empty)
[ 927.954479][ C0] Kernel Offset: disabled
On Mon 2020-09-28 11:07:52, Sergey Senozhatsky wrote:
> Cc-ing John and Steven
>
> On (20/09/27 11:12), Dmitry Vyukov wrote:
> > Hi printk maintainers,
> >
> > I've got the following out-of-bounds in printk code.
> > This is on next-20200925. Config is attached.
> > This is just on pr_cont("\n"). Something overreads the string.
> >
> > ==================================================================
> > BUG: KASAN: global-out-of-bounds in memchr+0x65/0x80 lib/string.c:1058
> > Read of size 1 at addr ffffffff8c68c860 by task swapper/0/0
>
> Thanks for the report. I think this should be fixed by
> https://lore.kernel.org/lkml/[email protected]/
I agree with Sergey. This looks very much like the same problem.
Best Regards,
Petr