On 4/20/21 2:59 AM, syzbot wrote: > Hello, > > syzbot has tested the proposed patch but the reproducer is still triggering an issue: > KASAN: null-ptr-deref Write in io_uring_cancel_sqpoll #syz test: git://git.kernel.dk/linux-block io_uring-5.13 > > ================================================================== > BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] > BUG: KASAN: null-ptr-deref in atomic_inc include/asm-generic/atomic-instrumented.h:240 [inline] > BUG: KASAN: null-ptr-deref in io_uring_cancel_sqpoll+0x150/0x310 fs/io_uring.c:8930 > Write of size 4 at addr 0000000000000114 by task iou-sqp-31588/31596 > > CPU: 0 PID: 31596 Comm: iou-sqp-31588 Not tainted 5.12.0-rc7-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:79 [inline] > dump_stack+0x141/0x1d7 lib/dump_stack.c:120 > __kasan_report mm/kasan/report.c:403 [inline] > kasan_report.cold+0x5f/0xd8 mm/kasan/report.c:416 > check_region_inline mm/kasan/generic.c:180 [inline] > kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 > instrument_atomic_read_write include/linux/instrumented.h:101 [inline] > atomic_inc include/asm-generic/atomic-instrumented.h:240 [inline] > io_uring_cancel_sqpoll+0x150/0x310 fs/io_uring.c:8930 > io_sq_thread+0x47e/0x1310 fs/io_uring.c:6873 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > ================================================================== > Kernel panic - not syncing: panic_on_warn set ... > CPU: 1 PID: 31596 Comm: iou-sqp-31588 Tainted: G B 5.12.0-rc7-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:79 [inline] > dump_stack+0x141/0x1d7 lib/dump_stack.c:120 > panic+0x306/0x73d kernel/panic.c:231 > end_report mm/kasan/report.c:102 [inline] > end_report.cold+0x5a/0x5a mm/kasan/report.c:88 > __kasan_report mm/kasan/report.c:406 [inline] > kasan_report.cold+0x6a/0xd8 mm/kasan/report.c:416 > check_region_inline mm/kasan/generic.c:180 [inline] > kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 > instrument_atomic_read_write include/linux/instrumented.h:101 [inline] > atomic_inc include/asm-generic/atomic-instrumented.h:240 [inline] > io_uring_cancel_sqpoll+0x150/0x310 fs/io_uring.c:8930 > io_sq_thread+0x47e/0x1310 fs/io_uring.c:6873 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > Tested on: > > commit: 734551df io_uring: fix shared sqpoll cancellation hangs > git tree: git://git.kernel.dk/linux-block for-5.13/io_uring > console output: https://syzkaller.appspot.com/x/log.txt?x=175fec6dd00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=601d16d8cd22e315 > dashboard link: https://syzkaller.appspot.com/bug?extid=47fc00967b06a3019bd2 > compiler: > -- Pavel Begunkov
