* [syzbot] KCSAN: data-race in call_rcu / rcu_gp_fqs_loop @ 2021-10-25 10:29 syzbot 2021-10-25 10:31 ` Marco Elver 0 siblings, 1 reply; 5+ messages in thread From: syzbot @ 2021-10-25 10:29 UTC (permalink / raw) To: linux-fsdevel, linux-kernel, syzkaller-bugs, viro Hello, syzbot found the following issue on: HEAD commit: 9c0c4d24ac00 Merge tag 'block-5.15-2021-10-22' of git://gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=159c4954b00000 kernel config: https://syzkaller.appspot.com/x/.config?x=6339b6ea86d89fd7 dashboard link: https://syzkaller.appspot.com/bug?extid=4dfb96a94317a78f44d9 compiler: Debian clang version 11.0.1-2, 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+4dfb96a94317a78f44d9@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in call_rcu / rcu_gp_fqs_loop write to 0xffffffff837342e0 of 8 bytes by task 11 on cpu 1: rcu_gp_fqs kernel/rcu/tree.c:1910 [inline] rcu_gp_fqs_loop+0x348/0x470 kernel/rcu/tree.c:1971 rcu_gp_kthread+0x25/0x1a0 kernel/rcu/tree.c:2130 kthread+0x262/0x280 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 read to 0xffffffff837342e0 of 8 bytes by task 379 on cpu 0: __call_rcu_core kernel/rcu/tree.c:2904 [inline] __call_rcu kernel/rcu/tree.c:3020 [inline] call_rcu+0x4c0/0x6d0 kernel/rcu/tree.c:3067 __dentry_kill+0x3ec/0x4e0 fs/dcache.c:596 dput+0xc6/0x360 fs/dcache.c:888 do_unlinkat+0x2a8/0x540 fs/namei.c:4172 __do_sys_unlink fs/namei.c:4217 [inline] __se_sys_unlink fs/namei.c:4215 [inline] __x64_sys_unlink+0x2c/0x30 fs/namei.c:4215 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000000000005c0d -> 0x0000000000005c0e Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 379 Comm: udevd Tainted: G W 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== --- 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@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [syzbot] KCSAN: data-race in call_rcu / rcu_gp_fqs_loop 2021-10-25 10:29 [syzbot] KCSAN: data-race in call_rcu / rcu_gp_fqs_loop syzbot @ 2021-10-25 10:31 ` Marco Elver 2021-10-26 14:07 ` Paul E. McKenney 0 siblings, 1 reply; 5+ messages in thread From: Marco Elver @ 2021-10-25 10:31 UTC (permalink / raw) To: syzbot, Paul E. McKenney, rcu Cc: linux-fsdevel, linux-kernel, syzkaller-bugs, viro +Cc Paul data race is in rcu code, presumably not yet discovered by rcutorture? On Mon, 25 Oct 2021 at 12:29, syzbot <syzbot+4dfb96a94317a78f44d9@syzkaller.appspotmail.com> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: 9c0c4d24ac00 Merge tag 'block-5.15-2021-10-22' of git://gi.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=159c4954b00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6339b6ea86d89fd7 > dashboard link: https://syzkaller.appspot.com/bug?extid=4dfb96a94317a78f44d9 > compiler: Debian clang version 11.0.1-2, 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+4dfb96a94317a78f44d9@syzkaller.appspotmail.com > > ================================================================== > BUG: KCSAN: data-race in call_rcu / rcu_gp_fqs_loop > > write to 0xffffffff837342e0 of 8 bytes by task 11 on cpu 1: > rcu_gp_fqs kernel/rcu/tree.c:1910 [inline] > rcu_gp_fqs_loop+0x348/0x470 kernel/rcu/tree.c:1971 > rcu_gp_kthread+0x25/0x1a0 kernel/rcu/tree.c:2130 > kthread+0x262/0x280 kernel/kthread.c:319 > ret_from_fork+0x1f/0x30 > > read to 0xffffffff837342e0 of 8 bytes by task 379 on cpu 0: > __call_rcu_core kernel/rcu/tree.c:2904 [inline] > __call_rcu kernel/rcu/tree.c:3020 [inline] > call_rcu+0x4c0/0x6d0 kernel/rcu/tree.c:3067 > __dentry_kill+0x3ec/0x4e0 fs/dcache.c:596 > dput+0xc6/0x360 fs/dcache.c:888 > do_unlinkat+0x2a8/0x540 fs/namei.c:4172 > __do_sys_unlink fs/namei.c:4217 [inline] > __se_sys_unlink fs/namei.c:4215 [inline] > __x64_sys_unlink+0x2c/0x30 fs/namei.c:4215 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > value changed: 0x0000000000005c0d -> 0x0000000000005c0e > > Reported by Kernel Concurrency Sanitizer on: > CPU: 0 PID: 379 Comm: udevd Tainted: G W 5.15.0-rc6-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > ================================================================== > > > --- > 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@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [syzbot] KCSAN: data-race in call_rcu / rcu_gp_fqs_loop 2021-10-25 10:31 ` Marco Elver @ 2021-10-26 14:07 ` Paul E. McKenney 2021-10-26 14:33 ` Paul E. McKenney 0 siblings, 1 reply; 5+ messages in thread From: Paul E. McKenney @ 2021-10-26 14:07 UTC (permalink / raw) To: Marco Elver Cc: syzbot, rcu, linux-fsdevel, linux-kernel, syzkaller-bugs, viro On Mon, Oct 25, 2021 at 12:31:53PM +0200, Marco Elver wrote: > +Cc Paul > > data race is in rcu code, presumably not yet discovered by rcutorture? Quite possibly, and I will take a look. Thank you for sending this along. Thanx, Paul > On Mon, 25 Oct 2021 at 12:29, syzbot > <syzbot+4dfb96a94317a78f44d9@syzkaller.appspotmail.com> wrote: > > > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 9c0c4d24ac00 Merge tag 'block-5.15-2021-10-22' of git://gi.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=159c4954b00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=6339b6ea86d89fd7 > > dashboard link: https://syzkaller.appspot.com/bug?extid=4dfb96a94317a78f44d9 > > compiler: Debian clang version 11.0.1-2, 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+4dfb96a94317a78f44d9@syzkaller.appspotmail.com > > > > ================================================================== > > BUG: KCSAN: data-race in call_rcu / rcu_gp_fqs_loop > > > > write to 0xffffffff837342e0 of 8 bytes by task 11 on cpu 1: > > rcu_gp_fqs kernel/rcu/tree.c:1910 [inline] > > rcu_gp_fqs_loop+0x348/0x470 kernel/rcu/tree.c:1971 > > rcu_gp_kthread+0x25/0x1a0 kernel/rcu/tree.c:2130 > > kthread+0x262/0x280 kernel/kthread.c:319 > > ret_from_fork+0x1f/0x30 > > > > read to 0xffffffff837342e0 of 8 bytes by task 379 on cpu 0: > > __call_rcu_core kernel/rcu/tree.c:2904 [inline] > > __call_rcu kernel/rcu/tree.c:3020 [inline] > > call_rcu+0x4c0/0x6d0 kernel/rcu/tree.c:3067 > > __dentry_kill+0x3ec/0x4e0 fs/dcache.c:596 > > dput+0xc6/0x360 fs/dcache.c:888 > > do_unlinkat+0x2a8/0x540 fs/namei.c:4172 > > __do_sys_unlink fs/namei.c:4217 [inline] > > __se_sys_unlink fs/namei.c:4215 [inline] > > __x64_sys_unlink+0x2c/0x30 fs/namei.c:4215 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x44/0xae > > > > value changed: 0x0000000000005c0d -> 0x0000000000005c0e > > > > Reported by Kernel Concurrency Sanitizer on: > > CPU: 0 PID: 379 Comm: udevd Tainted: G W 5.15.0-rc6-syzkaller #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > ================================================================== > > > > > > --- > > 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@googlegroups.com. > > > > syzbot will keep track of this issue. See: > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [syzbot] KCSAN: data-race in call_rcu / rcu_gp_fqs_loop 2021-10-26 14:07 ` Paul E. McKenney @ 2021-10-26 14:33 ` Paul E. McKenney 2021-10-26 14:39 ` Marco Elver 0 siblings, 1 reply; 5+ messages in thread From: Paul E. McKenney @ 2021-10-26 14:33 UTC (permalink / raw) To: Marco Elver Cc: syzbot, rcu, linux-fsdevel, linux-kernel, syzkaller-bugs, viro On Tue, Oct 26, 2021 at 07:07:30AM -0700, Paul E. McKenney wrote: > On Mon, Oct 25, 2021 at 12:31:53PM +0200, Marco Elver wrote: > > +Cc Paul > > > > data race is in rcu code, presumably not yet discovered by rcutorture? > > Quite possibly, and I will take a look. Thank you for sending this > along. And this is (allegedly) fixed by commit 2431774f04d10 ("rcu: Mark accesses to rcu_state.n_force_qs"), which is in -rcu and slated for the upcoming merge window. But yes, still a bug in mainline. Thanx, Paul > > On Mon, 25 Oct 2021 at 12:29, syzbot > > <syzbot+4dfb96a94317a78f44d9@syzkaller.appspotmail.com> wrote: > > > > > > Hello, > > > > > > syzbot found the following issue on: > > > > > > HEAD commit: 9c0c4d24ac00 Merge tag 'block-5.15-2021-10-22' of git://gi.. > > > git tree: upstream > > > console output: https://syzkaller.appspot.com/x/log.txt?x=159c4954b00000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=6339b6ea86d89fd7 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=4dfb96a94317a78f44d9 > > > compiler: Debian clang version 11.0.1-2, 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+4dfb96a94317a78f44d9@syzkaller.appspotmail.com > > > > > > ================================================================== > > > BUG: KCSAN: data-race in call_rcu / rcu_gp_fqs_loop > > > > > > write to 0xffffffff837342e0 of 8 bytes by task 11 on cpu 1: > > > rcu_gp_fqs kernel/rcu/tree.c:1910 [inline] > > > rcu_gp_fqs_loop+0x348/0x470 kernel/rcu/tree.c:1971 > > > rcu_gp_kthread+0x25/0x1a0 kernel/rcu/tree.c:2130 > > > kthread+0x262/0x280 kernel/kthread.c:319 > > > ret_from_fork+0x1f/0x30 > > > > > > read to 0xffffffff837342e0 of 8 bytes by task 379 on cpu 0: > > > __call_rcu_core kernel/rcu/tree.c:2904 [inline] > > > __call_rcu kernel/rcu/tree.c:3020 [inline] > > > call_rcu+0x4c0/0x6d0 kernel/rcu/tree.c:3067 > > > __dentry_kill+0x3ec/0x4e0 fs/dcache.c:596 > > > dput+0xc6/0x360 fs/dcache.c:888 > > > do_unlinkat+0x2a8/0x540 fs/namei.c:4172 > > > __do_sys_unlink fs/namei.c:4217 [inline] > > > __se_sys_unlink fs/namei.c:4215 [inline] > > > __x64_sys_unlink+0x2c/0x30 fs/namei.c:4215 > > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > > do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 > > > entry_SYSCALL_64_after_hwframe+0x44/0xae > > > > > > value changed: 0x0000000000005c0d -> 0x0000000000005c0e > > > > > > Reported by Kernel Concurrency Sanitizer on: > > > CPU: 0 PID: 379 Comm: udevd Tainted: G W 5.15.0-rc6-syzkaller #0 > > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > > ================================================================== > > > > > > > > > --- > > > 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@googlegroups.com. > > > > > > syzbot will keep track of this issue. See: > > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [syzbot] KCSAN: data-race in call_rcu / rcu_gp_fqs_loop 2021-10-26 14:33 ` Paul E. McKenney @ 2021-10-26 14:39 ` Marco Elver 0 siblings, 0 replies; 5+ messages in thread From: Marco Elver @ 2021-10-26 14:39 UTC (permalink / raw) To: paulmck; +Cc: syzbot, rcu, linux-fsdevel, linux-kernel, syzkaller-bugs, viro On Tue, 26 Oct 2021 at 16:33, Paul E. McKenney <paulmck@kernel.org> wrote: > On Tue, Oct 26, 2021 at 07:07:30AM -0700, Paul E. McKenney wrote: > > On Mon, Oct 25, 2021 at 12:31:53PM +0200, Marco Elver wrote: > > > +Cc Paul > > > > > > data race is in rcu code, presumably not yet discovered by rcutorture? > > > > Quite possibly, and I will take a look. Thank you for sending this > > along. > > And this is (allegedly) fixed by commit 2431774f04d10 ("rcu: Mark accesses > to rcu_state.n_force_qs"), which is in -rcu and slated for the upcoming > merge window. But yes, still a bug in mainline. Thanks for confirming, then the latest incarnation of it must then be a dup, and I'll mark it fixed: #syz fix: rcu: Mark accesses to rcu_state.n_force_qs Apologies I missed there was a previous report and your fix. Thanks, -- Marco ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-10-26 14:40 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-10-25 10:29 [syzbot] KCSAN: data-race in call_rcu / rcu_gp_fqs_loop syzbot 2021-10-25 10:31 ` Marco Elver 2021-10-26 14:07 ` Paul E. McKenney 2021-10-26 14:33 ` Paul E. McKenney 2021-10-26 14:39 ` Marco Elver
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