Subject: [syzbot] WARNING in print_tainted

From: syzbot <[email-masked]>
Date: Mon, 19 Dec 2022 02:37:49 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    77856d911a8c Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15cddf1f880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b3c64cceddc7988
dashboard link: https://syzkaller.appspot.com/bug?extid=5aed6c3aaba661f5b917
compiler:       arm-linux-gnueabi-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm

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-masked]

------------[ cut here ]------------
WARNING: CPU: 1 PID: 0 at net/can/isotp.c:920 isotp_tx_timer_handler+0xe0/0x148 net/can/isotp.c:920
can-isotp: tx timer state 00000000 cfecho 00000000
Modules linked in:
Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.0-syzkaller #0
Hardware name: ARM-Versatile Express
Backtrace: frame pointer underflow
[<81764cd8>] (dump_backtrace) from [<81764dcc>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:256)
 r7:81d77dbc r6:824229dc r5:60000193 r4:81d86398
[<81764db4>] (show_stack) from [<817811c0>] (__dump_stack lib/dump_stack.c:88 [inline])
[<81764db4>] (show_stack) from [<817811c0>] (dump_stack_lvl+0x48/0x54 lib/dump_stack.c:106)
[<81781178>] (dump_stack_lvl) from [<817811e4>] (dump_stack+0x18/0x1c lib/dump_stack.c:113)
 r5:00000000 r4:82646d14
[<817811cc>] (dump_stack) from [<81765974>] (panic+0x11c/0x360 kernel/panic.c:315)
[<81765858>] (panic) from [<802416b0>] (print_tainted+0x0/0xa0 kernel/panic.c:236)
 r3:00000001 r2:8240c488 r1:81d7031c r0:81d77dbc
 r7:81611f88
[<80241634>] (check_panic_on_warn) from [<802418a4>] (__warn+0x7c/0x18c kernel/panic.c:661)
[<80241828>] (__warn) from [<81765c54>] (warn_slowpath_fmt+0x9c/0xd4 kernel/panic.c:691)
 r8:00000009 r7:81611f88 r6:00000398 r5:81f315e8 r4:81f315bc
[<81765bbc>] (warn_slowpath_fmt) from [<81611f88>] (isotp_tx_timer_handler+0xe0/0x148 net/can/isotp.c:920)
 r8:dddde3a0 r7:000000a0 r6:dddde300 r5:00000000 r4:85280278
[<81611ea8>] (isotp_tx_timer_handler) from [<802e8efc>] (__run_hrtimer kernel/time/hrtimer.c:1685 [inline])
[<81611ea8>] (isotp_tx_timer_handler) from [<802e8efc>] (__hrtimer_run_queues+0x1b0/0x46c kernel/time/hrtimer.c:1749)
 r5:dddde3e0 r4:85280278
[<802e8d4c>] (__hrtimer_run_queues) from [<802e9244>] (hrtimer_run_softirq+0x8c/0xb8 kernel/time/hrtimer.c:1766)
 r10:828f3980 r9:00000101 r8:00000100 r7:00000000 r6:00000000 r5:20000113
 r4:dddde300
[<802e91b8>] (hrtimer_run_softirq) from [<80201338>] (__do_softirq+0x16c/0x498 kernel/softirq.c:571)
 r7:df85df08 r6:00000008 r5:00000009 r4:824040a0
[<802011cc>] (__do_softirq) from [<8024a3c8>] (invoke_softirq kernel/softirq.c:445 [inline])
[<802011cc>] (__do_softirq) from [<8024a3c8>] (__irq_exit_rcu kernel/softirq.c:650 [inline])
[<802011cc>] (__do_softirq) from [<8024a3c8>] (__irq_exit_rcu kernel/softirq.c:640 [inline])
[<802011cc>] (__do_softirq) from [<8024a3c8>] (irq_exit+0x9c/0xe8 kernel/softirq.c:674)
 r10:825d998e r9:828f3980 r8:00000000 r7:df85df08 r6:81f3b940 r5:81f3b958
 r4:822aac40
[<8024a32c>] (irq_exit) from [<817818b8>] (generic_handle_arch_irq+0x7c/0x80 kernel/irq/handle.c:240)
 r5:81f3b958 r4:822aac1c
[<8178183c>] (generic_handle_arch_irq) from [<817371d4>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40)
 r9:828f3980 r8:00000000 r7:df85df3c r6:ffffffff r5:60000013 r4:80208f08
[<817371b8>] (call_with_stack) from [<80200b44>] (__irq_svc+0x84/0xac arch/arm/kernel/entry-armv.S:221)
Exception stack(0xdf85df08 to 0xdf85df50)
df00:                   00000001 00000000 0048bc31 8021c240 828f3980 00000001
df20: 828f3980 8240c5e0 00000000 00000000 825d998e df85df64 df85df68 df85df58
df40: 80208f04 80208f08 60000013 ffffffff
[<80208ec8>] (arch_cpu_idle) from [<8178bb9c>] (default_idle_call+0x38/0x1b4 kernel/sched/idle.c:109)
[<8178bb64>] (default_idle_call) from [<8028f138>] (cpuidle_idle_call kernel/sched/idle.c:191 [inline])
[<8178bb64>] (default_idle_call) from [<8028f138>] (do_idle+0x218/0x2a0 kernel/sched/idle.c:303)
 r7:8240c5e0 r6:828f3980 r5:8240c49c r4:00000001
[<8028ef20>] (do_idle) from [<8028f4dc>] (cpu_startup_entry+0x20/0x24 kernel/sched/idle.c:400)
 r10:00000000 r9:412fc0f1 r8:80003010 r7:82646464 r6:828f3980 r5:00000001
 r4:0000009c
[<8028f4bc>] (cpu_startup_entry) from [<80210b70>] (secondary_start_kernel+0x138/0x194 arch/arm/kernel/smp.c:481)
[<80210a38>] (secondary_start_kernel) from [<80201714>] (__enable_mmu+0x0/0xc arch/arm/kernel/head.S:438)
 r7:82646464 r6:30c0387d r5:00000000 r4:82a0d6c0
Rebooting in 86400 seconds..

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