Hello, syzbot found the following issue on: HEAD commit: df0cc57e057f Linux 5.16 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12a89d2db00000 kernel config: https://syzkaller.appspot.com/x/.config?x=ea1f52f5503d3ac3 dashboard link: https://syzkaller.appspot.com/bug?extid=25ca556057c68f8a03a2 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 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: syzbot+25ca556057c68f8a03a2@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_write include/linux/instrumented.h:86 [inline] BUG: KASAN: null-ptr-deref in clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] BUG: KASAN: null-ptr-deref in kcm_tx_work+0xff/0x160 net/kcm/kcmsock.c:741 Write of size 8 at addr 0000000000000008 by task kworker/u4:47/7955 CPU: 1 PID: 7955 Comm: kworker/u4:47 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: kkcmd kcm_tx_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:437 [inline] kasan_report.cold+0x66/0xdf mm/kasan/report.c:450 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 instrument_atomic_write include/linux/instrumented.h:86 [inline] clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] kcm_tx_work+0xff/0x160 net/kcm/kcmsock.c:741 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> ================================================================== Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7955 Comm: kworker/u4:47 Tainted: G B 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: kkcmd kcm_tx_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 panic+0x2b0/0x6dd kernel/panic.c:232 end_report.cold+0x63/0x6f mm/kasan/report.c:128 __kasan_report mm/kasan/report.c:440 [inline] kasan_report.cold+0x71/0xdf mm/kasan/report.c:450 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 instrument_atomic_write include/linux/instrumented.h:86 [inline] clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] kcm_tx_work+0xff/0x160 net/kcm/kcmsock.c:741 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> Kernel Offset: disabled Rebooting in 86400 seconds.. --- 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 syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
