ci2 starts bisection 2026-08-16 06:26:17.633709794 +0000 UTC m=+110129.631947906
bisecting fixing commit since c86c4726e7f044ab73b493c6f00527aafef640cd
building syzkaller on d78ea535f456172a095a6d211ee0a2de1d049968
ensuring issue is reproducible on original commit c86c4726e7f044ab73b493c6f00527aafef640cd
testing commit c86c4726e7f044ab73b493c6f00527aafef640cd gcc
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44
kernel signature: 2fa7cc478552bbc28de583d6764c6efec3dd58f02ebc889991c368fff647a4fc
run #0: crashed: INFO: rcu detected stall in batadv_nc_worker
run #1: crashed: INFO: rcu detected stall in filemap_fault
run #2: crashed: INFO: rcu detected stall in cleanup_net
run #3: crashed: INFO: rcu detected stall in sys_unlink
run #4: crashed: INFO: rcu detected stall in batadv_nc_worker
run #5: crashed: INFO: rcu detected stall in corrupted
run #6: crashed: INFO: rcu detected stall in sys_mlock
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in filemap_fault
run #9: crashed: INFO: rcu detected stall in filemap_fault
run #10: crashed: INFO: rcu detected stall in batadv_nc_worker
run #11: crashed: INFO: rcu detected stall in corrupted
run #12: crashed: INFO: rcu detected stall in batadv_nc_worker
run #13: crashed: INFO: rcu detected stall in cleanup_net
run #14: crashed: INFO: rcu detected stall in corrupted
run #15: crashed: INFO: rcu detected stall in corrupted
run #16: crashed: INFO: rcu detected stall in batadv_nc_worker
run #17: crashed: INFO: rcu detected stall in sys_mlock
run #18: crashed: INFO: rcu detected stall in filemap_fault
run #19: crashed: no output from test machine
representative crash: INFO: rcu detected stall in batadv_nc_worker, types: [HANG]
check whether we can drop unnecessary instrumentation
disabling configs for [ubsan bug_or_warning kasan locking atomic_sleep memleak], they are not needed
testing commit c86c4726e7f044ab73b493c6f00527aafef640cd gcc
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44
kernel signature: ebcc7fbb85cbe99d421f14e797be15a1097346952efe63b4370fc442ae7f2402
run #0: crashed: INFO: rcu detected stall in corrupted
run #1: crashed: INFO: rcu detected stall in sys_mlock
run #2: crashed: INFO: rcu detected stall in corrupted
run #3: crashed: INFO: rcu detected stall in corrupted
run #4: crashed: INFO: rcu detected stall in corrupted
run #5: crashed: INFO: rcu detected stall in filemap_fault
run #6: crashed: INFO: rcu detected stall in filemap_fault
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in filemap_fault
run #9: crashed: INFO: rcu detected stall in sys_mlock
representative crash: INFO: rcu detected stall in corrupted, types: [HANG]
the bug reproduces without the instrumentation
disabling configs for [ubsan bug_or_warning kasan locking atomic_sleep memleak], they are not needed
kconfig minimization: base=3707 full=7426 leaves diff=2100
split chunks (needed=false): <2100>
split chunk #0 of len 2100 into 5 parts
testing without sub-chunk 1/5
disabling configs for [bug_or_warning kasan locking atomic_sleep memleak ubsan], they are not needed
testing commit c86c4726e7f044ab73b493c6f00527aafef640cd gcc
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44
kernel signature: 8a46c296ba06571fa196388648adafd0904c417d5bb3150f5d9dede17d14719f
run #0: crashed: INFO: rcu detected stall in sys_mlock
run #1: crashed: INFO: rcu detected stall in corrupted
run #2: crashed: INFO: rcu detected stall in corrupted
run #3: crashed: INFO: rcu detected stall in sys_mlock
run #4: crashed: INFO: rcu detected stall in sys_mlock
run #5: crashed: INFO: rcu detected stall in sys_mlock
run #6: crashed: INFO: rcu detected stall in sys_mlock
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in sys_mlock
run #9: crashed: INFO: rcu detected stall in corrupted
representative crash: INFO: rcu detected stall in sys_mlock, types: [HANG]
the chunk can be dropped
testing without sub-chunk 2/5
disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed
testing commit c86c4726e7f044ab73b493c6f00527aafef640cd gcc
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44
kernel signature: cadabe994814dd632baed3ad5fc4ac96ec0023f96b0daa5a0c210c64899bfbce
run #0: crashed: INFO: rcu detected stall in filemap_fault
run #1: crashed: INFO: rcu detected stall in sys_mlock
run #2: crashed: INFO: rcu detected stall in corrupted
run #3: crashed: INFO: rcu detected stall in sys_mlock
run #4: crashed: INFO: rcu detected stall in corrupted
run #5: crashed: INFO: rcu detected stall in filemap_fault
run #6: crashed: INFO: rcu detected stall in filemap_fault
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in corrupted
run #9: crashed: INFO: rcu detected stall in filemap_fault
representative crash: INFO: rcu detected stall in filemap_fault, types: [HANG]
the chunk can be dropped
testing without sub-chunk 3/5
disabling configs for [kasan locking atomic_sleep memleak ubsan bug_or_warning], they are not needed
testing commit c86c4726e7f044ab73b493c6f00527aafef640cd gcc
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44
kernel signature: f65e8b44d9c6c50aa217dd3d936f0bfbd4d96158c9710d4f64a64cd9f32f7a87
run #0: crashed: INFO: rcu detected stall in filemap_fault
run #1: crashed: INFO: rcu detected stall in corrupted
run #2: crashed: INFO: rcu detected stall in corrupted
run #3: crashed: INFO: rcu detected stall in sys_mlock
run #4: crashed: INFO: rcu detected stall in filemap_fault
run #5: crashed: INFO: rcu detected stall in sys_mlock
run #6: crashed: INFO: rcu detected stall in corrupted
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in filemap_fault
run #9: crashed: INFO: rcu detected stall in filemap_fault
representative crash: INFO: rcu detected stall in filemap_fault, types: [HANG]
the chunk can be dropped
testing without sub-chunk 4/5
disabling configs for [bug_or_warning kasan locking atomic_sleep memleak ubsan], they are not needed
testing commit c86c4726e7f044ab73b493c6f00527aafef640cd gcc
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44
kernel signature: 6afb243906c134a174c82efec0cf04251be1226e9c30b149d36c09c30f4cc1d0
run #0: crashed: INFO: rcu detected stall in filemap_fault
run #1: crashed: INFO: rcu detected stall in filemap_fault
run #2: crashed: INFO: rcu detected stall in filemap_fault
run #3: crashed: INFO: rcu detected stall in corrupted
run #4: crashed: INFO: rcu detected stall in sys_mlock
run #5: crashed: INFO: rcu detected stall in filemap_fault
run #6: crashed: INFO: rcu detected stall in sys_mlock
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in filemap_fault
run #9: crashed: INFO: rcu detected stall in filemap_fault
representative crash: INFO: rcu detected stall in filemap_fault, types: [HANG]
the chunk can be dropped
testing without sub-chunk 5/5
disabling configs for [ubsan bug_or_warning kasan locking atomic_sleep memleak], they are not needed
testing commit c86c4726e7f044ab73b493c6f00527aafef640cd gcc
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44
kernel signature: 14cc4263033940d45a4c251463e274f388b381a4a74f160f20a76fceda3845d8
run #0: crashed: INFO: rcu detected stall in sys_mlock
run #1: crashed: INFO: rcu detected stall in filemap_fault
run #2: crashed: INFO: rcu detected stall in filemap_fault
run #3: crashed: INFO: rcu detected stall in filemap_fault
run #4: crashed: INFO: rcu detected stall in filemap_fault
run #5: crashed: INFO: rcu detected stall in filemap_fault
run #6: crashed: INFO: rcu detected stall in sys_mlock
run #7: crashed: INFO: rcu detected stall in sys_mlock
run #8: crashed: INFO: rcu detected stall in sys_mlock
run #9: crashed: INFO: rcu detected stall in corrupted
representative crash: INFO: rcu detected stall in sys_mlock, types: [HANG]
the chunk can be dropped
disabling configs for [atomic_sleep memleak ubsan bug_or_warning kasan locking], they are not needed
testing current HEAD aabd761612dbeb7d40750d485da219d11433718a
testing commit aabd761612dbeb7d40750d485da219d11433718a gcc
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44
kernel signature: 77dc4467e86ad8c230cc90d67db8d1bb1e2c622fdef858c719dab28eebc0e59e
run #0: crashed: INFO: rcu detected stall in filemap_fault
run #1: crashed: INFO: rcu detected stall in sys_mlock
run #2: crashed: INFO: rcu detected stall in filemap_fault
run #3: crashed: INFO: rcu detected stall in filemap_fault
run #4: crashed: INFO: rcu detected stall in filemap_fault
run #5: crashed: INFO: rcu detected stall in filemap_fault
run #6: crashed: INFO: rcu detected stall in filemap_fault
run #7: crashed: INFO: rcu detected stall in filemap_fault
run #8: crashed: INFO: rcu detected stall in filemap_fault
run #9: crashed: INFO: rcu detected stall in filemap_fault
representative crash: INFO: rcu detected stall in filemap_fault, types: [HANG]
crash still not fixed/happens on the oldest tested release
revisions tested: 8, total time: 2h1m22.662132311s (build: 21m46.811898768s, test: 1h31m9.577462426s)
crash still not fixed or there were kernel test errors
commit msg: Linux 5.15.215
crash: INFO: rcu detected stall in filemap_fault
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=b69/1/0x4000000000000000 softirq=4775/4776 fqs=0
(t=10001 jiffies g=1005 q=300)
rcu: rcu_sched kthread timer wakeup didn't happen for 10001 jiffies! g1005 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=740
rcu: rcu_sched kthread starved for 10004 jiffies! g1005 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_sched state:I stack:14376 pid: 12 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x2b8/0x790 kernel/sched/core.c:6395
schedule+0x53/0x90 kernel/sched/core.c:6478
schedule_timeout+0xaf/0x140 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0xe2/0x320 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x77/0xe0 kernel/rcu/tree.c:2145
kthread+0x10b/0x130 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3456 Comm: syz.1.30 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__lock_release kernel/locking/lockdep.c:5330 [inline]
RIP: 0010:lock_release+0xdd/0x220 kernel/locking/lockdep.c:5643
Code: 48 85 c0 0f 84 30 01 00 00 66 f7 40 22 f0 ff 74 0d 66 83 68 22 10 66 f7 40 22 f0 ff 75 3c 8b 54 24 04 41 89 94 24 20 0a 00 00 <48> 8b 00 49 89 84 24 18 0a 00 00 41 8d 46 ff 39 d0 74 1d 83 c2 01
RSP: 0018:ffffc90001237d38 EFLAGS: 00000046
RAX: ffff88810cb92550 RBX: 0000000000000246 RCX: ffffc90001237d3c
RDX: 0000000000000001 RSI: ffff88810dc6fa58 RDI: ffff88810cb92550
RBP: ffff88810dc6fa58 R08: 0000000000000029 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000008 R12: ffff88810cb91b00
R13: ffffffff811c3545 R14: 0000000000000002 R15: ffff8881194b3000
FS: 00007f9f5ece86c0(0000) GS:ffff888237d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557b0e1958 CR3: 0000000119483000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_unlock include/linux/spinlock_api_smp.h:150 [inline]
_raw_spin_unlock+0x12/0x20 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:404 [inline]
follow_page_pte mm/gup.c:642 [inline]
follow_pmd_mask mm/gup.c:705 [inline]
follow_pud_mask mm/gup.c:788 [inline]
follow_p4d_mask mm/gup.c:814 [inline]
follow_page_mask+0x2f5/0x5e0 mm/gup.c:873
__get_user_pages+0x1d7/0x620 mm/gup.c:1195
populate_vma_page_range+0xb2/0xf0 mm/gup.c:1529
__mm_populate+0xa4/0x180 mm/gup.c:1638
do_mlock+0x103/0x250 mm/mlock.c:688
__do_sys_mlock mm/mlock.c:696 [inline]
__se_sys_mlock mm/mlock.c:694 [inline]
__x64_sys_mlock+0x12/0x20 mm/mlock.c:694
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x33/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9f5ee86e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9f5ece8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000095
RAX: ffffffffffffffda RBX: 00007f9f5f10efa0 RCX: 00007f9f5ee86e59
RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000200000000000
RBP: 00007f9f5ef1ce6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9f5f10f038 R14: 00007f9f5f10efa0 R15: 00007fffaa123db8
NMI backtrace for cpu 0
sched: RT throttling activated
CPU: 0 PID: 3466 Comm: syz.7.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x41/0x5e lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x32/0x80 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x81/0x90 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_dump_cpu_stacks+0xa5/0xd3 kernel/rcu/tree_stall.h:349
print_cpu_stall kernel/rcu/tree_stall.h:633 [inline]
check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq.cold+0xc7/0x1e7 kernel/rcu/tree.c:2619
update_process_times+0x87/0xc0 kernel/time/timer.c:2021
tick_sched_handle+0x1d/0x50 kernel/time/tick-sched.c:254
tick_sched_timer+0x5c/0x70 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x11c/0x290 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x109/0x230 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x63/0x100 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x65/0x90 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:rcu_is_watching+0x11/0x20 kernel/rcu/tree.c:1123
Code: e5 c3 69 01 89 06 48 8b 05 74 c3 69 01 48 89 02 c3 0f 1f 84 00 00 00 00 00 48 c7 c0 08 bc 02 00 65 48 03 05 49 bd f3 7e 8b 00 <83> e0 01 c3 66 66 2e 0f 1f 84 00 00 00 00 00 c3 66 66 2e 0f 1f 84
RSP: 0018:ffffc900013178b0 EFLAGS: 00000282
RAX: 0000000000005b69 RBX: ffffc900013179d4 RCX: 0000000035aab5c6
RDX: 0000000000000001 RSI: ffffffff8134637a RDI: ffff88810b685478
RBP: ffff88810b685478 R08: 00000000000004ec R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000008 R12: 0000000000000000
R13: ffffffff8134637a R14: ffffc900013179d0 R15: ffff88810b685590
trace_lock_release include/trace/events/lock.h:58 [inline]
lock_release+0x1b1/0x220 kernel/locking/lockdep.c:5634
__raw_spin_unlock include/linux/spinlock_api_smp.h:150 [inline]
_raw_spin_unlock+0x12/0x20 kernel/locking/spinlock.c:186
fat_cache_add fs/fat/cache.c:138 [inline]
fat_get_cluster+0x2aa/0x440 fs/fat/cache.c:285
fat_bmap_cluster fs/fat/cache.c:299 [inline]
fat_get_mapped_cluster+0x8b/0x100 fs/fat/cache.c:320
__fat_get_block fs/fat/inode.c:129 [inline]
fat_get_block+0x5d/0x210 fs/fat/inode.c:190
do_mpage_readpage+0x2d6/0x850 fs/mpage.c:231
mpage_readpage+0x46/0xa0 fs/mpage.c:408
filemap_read_page+0x50/0x170 mm/filemap.c:2386
filemap_fault+0x83c/0x970 mm/filemap.c:3174
__do_fault+0x2d/0xd0 mm/memory.c:3928
do_read_fault mm/memory.c:4264 [inline]
do_fault mm/memory.c:4392 [inline]
handle_pte_fault mm/memory.c:4650 [inline]
__handle_mm_fault+0x693/0xd00 mm/memory.c:4785
handle_mm_fault+0xfa/0x290 mm/memory.c:4883
faultin_page mm/gup.c:976 [inline]
__get_user_pages+0x24a/0x620 mm/gup.c:1197
populate_vma_page_range+0xb2/0xf0 mm/gup.c:1529
__mm_populate+0xa4/0x180 mm/gup.c:1638
do_mlock+0x103/0x250 mm/mlock.c:688
__do_sys_mlock mm/mlock.c:696 [inline]
__se_sys_mlock mm/mlock.c:694 [inline]
__x64_sys_mlock+0x12/0x20 mm/mlock.c:694
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x33/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc77be0ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc77bc6e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000095
RAX: ffffffffffffffda RBX: 00007fc77c094fa0 RCX: 00007fc77be0ce59
RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000200000000000
RBP: 00007fc77bea2e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc77c095038 R14: 00007fc77c094fa0 R15: 00007ffe95d41fc8