syzbot


BUG: soft lockup in generic_file_write_iter

Status: moderation: reported on 2022/12/02 01:50
Reported-by: syzbot+0637d73bbc422e2b91ba@syzkaller.appspotmail.com
First crash: 70d, last: 31d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in generic_file_write_iter (6) 2 412d 469d 0/24 closed as invalid on 2022/02/08 09:50
upstream INFO: rcu detected stall in generic_file_write_iter (3) 1 1160d 1159d 0/24 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in generic_file_write_iter (2) 2 1374d 1414d 0/24 auto-closed as invalid on 2019/10/25 09:01
upstream INFO: rcu detected stall in generic_file_write_iter (4) 1 1092d 1088d 0/24 auto-closed as invalid on 2020/05/09 11:43
upstream INFO: rcu detected stall in generic_file_write_iter 58 1438d 1580d 0/24 closed as dup on 2018/10/27 15:28
upstream INFO: rcu detected stall in generic_file_write_iter (5) 2 927d 934d 0/24 auto-closed as invalid on 2020/10/22 01:02

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [syz-executor.0:27335]
Modules linked in:
irq event stamp: 18338
hardirqs last  enabled at (18337): [<ffff80000ca05bc8>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (18337): [<ffff80000ca05bc8>] exit_to_kernel_mode+0x38/0x120 arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (18338): [<ffff80000ca07844>] __el1_irq arch/arm64/kernel/entry-common.c:468 [inline]
hardirqs last disabled at (18338): [<ffff80000ca07844>] el1_interrupt+0x24/0x54 arch/arm64/kernel/entry-common.c:486
softirqs last  enabled at (18284): [<ffff8000080109d4>] _stext+0x9d4/0x107c
softirqs last disabled at (18107): [<ffff800008019cb0>] ____do_softirq+0x10/0x20 arch/arm64/kernel/irq.c:79
CPU: 0 PID: 27335 Comm: syz-executor.0 Not tainted 6.1.0-rc6-syzkaller-00337-gbf82d38c91f8 #0
Hardware name: linux,dummy-virt (DT)
pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __arch_copy_from_user+0x1b0/0x230 arch/arm64/lib/copy_template.S:164
lr : copyin lib/iov_iter.c:183 [inline]
lr : copyin+0xb8/0x120 lib/iov_iter.c:175
sp : ffff800013f27830
x29: ffff800013f27830 x28: ffff800013f27c30 x27: ffff80000dc70d98
x26: 00000000000a6000 x25: ffff800013f27c38 x24: ffff00000619c000
x23: 0000ffff7ca00000 x22: 0000ffff7caa6000 x21: ffff00000619c000
x20: 0000ffff7caa6000 x19: 0000000000001000 x18: ffff00006a9a4c00
x17: ffff80005ca0e000 x16: ffff800010ce8000 x15: 0000ffff7caa6000
x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffff00000619c7c0
x5 : ffff00000619d000 x4 : 0000000000000000 x3 : ffff8000091077c8
x2 : 00000000000007c0 x1 : 0000ffff7caa6800 x0 : ffff00000619c000
Call trace:
 __arch_copy_from_user+0x1b0/0x230 arch/arm64/lib/copy_template.S:158
 copy_page_from_iter_atomic+0x1d8/0xd00 lib/iov_iter.c:820
 generic_perform_write+0x218/0x3ec mm/filemap.c:3761
 __generic_file_write_iter+0x1e8/0x394 mm/filemap.c:3881
 generic_file_write_iter+0xc0/0x29c mm/filemap.c:3913
 call_write_iter include/linux/fs.h:2191 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x4c4/0x740 fs/read_write.c:584
 ksys_write+0xec/0x1d0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x6c/0xa0 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x6c/0x260 arch/arm64/kernel/syscall.c:52
 el0_svc_common.constprop.0+0xc4/0x254 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x50/0x14c arch/arm64/kernel/syscall.c:206
 el0_svc+0x54/0x140 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0xb8/0xc0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci-qemu2-arm64 2022/11/28 01:42 upstream bf82d38c91f8 f4470a7b .config console log report info BUG: soft lockup in generic_file_write_iter
ci-upstream-linux-next-kasan-gce-root 2023/01/05 19:11 linux-next cc3c08b41a9c 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] INFO: rcu detected stall in generic_file_write_iter
* Struck through repros no longer work on HEAD.