==================================================================
BUG: KASAN: use-after-free in bcm_can_tx+0x726/0x800 net/can/bcm.c:295
Read of size 4 at addr ffff88809e6fca44 by task syz-executor.4/8124
CPU: 1 PID: 8124 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
kasan_report mm/kasan/report.c:412 [inline]
__asan_report_load4_noabort+0x88/0x90 mm/kasan/report.c:432
bcm_can_tx+0x726/0x800 net/can/bcm.c:295
bcm_tx_timeout_tsklet+0x1f0/0x3a0 net/can/bcm.c:414
tasklet_action_common.constprop.0+0x265/0x360 kernel/softirq.c:522
__do_softirq+0x265/0x980 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:372 [inline]
irq_exit+0x215/0x260 kernel/softirq.c:412
exiting_irq arch/x86/include/asm/apic.h:536 [inline]
smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x50/0x80 kernel/locking/spinlock.c:192
Code: c0 98 82 f1 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d 01 31 d8 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 26 1b 28 f9 65 8b 05 9f 8d e8 77 85 c0 74 02 5d
RSP: 0018:ffff88809ccb7b10 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff13e3053 RBX: ffff88809cc6c580 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff88809cc6ce04
RBP: ffff8880ba12b0c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ba12b0c0
R13: ffff8880b251a640 R14: ffff88809b4df1c0 R15: 0000000000000000
finish_lock_switch kernel/sched/core.c:2578 [inline]
finish_task_switch+0x146/0x760 kernel/sched/core.c:2678
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x88f/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
freezable_schedule include/linux/freezer.h:172 [inline]
do_nanosleep+0x264/0x6c0 kernel/time/hrtimer.c:1755
hrtimer_nanosleep+0x24d/0x570 kernel/time/hrtimer.c:1809
common_nsleep+0x23/0x30 kernel/time/posix-timers.c:1204
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1231 [inline]
__se_sys_clock_nanosleep+0x261/0x360 kernel/time/posix-timers.c:1209
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f42ab4a52d1
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f
RSP: 002b:00007ffe1c0a1360 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000000000000077b RCX: 00007f42ab4a52d1
RDX: 00007ffe1c0a13a0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe1c0a142c R08: 0000000000000000 R09: 0000007257d82b56
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 000000000006c1d3 R14: 0000000000000009 R15: 00007ffe1c0a1490
Allocated by task 28135:
kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
kmalloc include/linux/slab.h:515 [inline]
kzalloc include/linux/slab.h:709 [inline]
bcm_tx_setup net/can/bcm.c:947 [inline]
bcm_sendmsg+0x25d7/0x4150 net/can/bcm.c:1386
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg+0xc3/0x120 net/socket.c:661
___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227
__sys_sendmsg net/socket.c:2265 [inline]
__do_sys_sendmsg net/socket.c:2274 [inline]
__se_sys_sendmsg net/socket.c:2272 [inline]
__x64_sys_sendmsg+0x132/0x220 net/socket.c:2272
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 28135:
__cache_free mm/slab.c:3503 [inline]
kfree+0xcc/0x210 mm/slab.c:3822
bcm_release+0x260/0x950 net/can/bcm.c:1561
__sock_release+0xcd/0x2a0 net/socket.c:599
sock_close+0x15/0x20 net/socket.c:1214
__fput+0x2ce/0x890 fs/file_table.c:278
task_work_run+0x148/0x1c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0xbf3/0x2be0 kernel/exit.c:870
do_group_exit+0x125/0x310 kernel/exit.c:967
get_signal+0x3f2/0x1f70 kernel/signal.c:2589
do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799
exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff88809e6fc900
which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 324 bytes inside of
1024-byte region [ffff88809e6fc900, ffff88809e6fcd00)
The buggy address belongs to the page:
page:ffffea000279bf00 count:1 mapcount:0 mapping:ffff88813bff0ac0 index:0xffff88809e6fd200 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea0002a73a88 ffffea00026c2488 ffff88813bff0ac0
raw: ffff88809e6fd200 ffff88809e6fc000 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88809e6fc900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88809e6fc980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809e6fca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88809e6fca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88809e6fcb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 5 bytes skipped:
0: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx
7: fc ff df
a: 48 c1 e8 03 shr $0x3,%rax
e: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1)
12: 75 31 jne 0x45
14: 48 83 3d 01 31 d8 01 cmpq $0x0,0x1d83101(%rip) # 0x1d8311d
1b: 00
1c: 74 25 je 0x43
1e: fb sti
1f: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
* 25: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction
2a: e8 26 1b 28 f9 callq 0xf9281b55
2f: 65 8b 05 9f 8d e8 77 mov %gs:0x77e88d9f(%rip),%eax # 0x77e88dd5
36: 85 c0 test %eax,%eax
38: 74 02 je 0x3c
3a: 5d pop %rbp