syzbot


BUG: scheduling while atomic in __synchronize_srcu

Status: upstream: reported C repro on 2026/04/09 18:30
Subsystems: kvmarm
[Documentation on labels]
Reported-by: syzbot+12b178b7c756664d2518@syzkaller.appspotmail.com
First crash: 63d, last: 45d
✨ AI Jobs (4)
ID Workflow Result Correct Ext Bug ID Bug Created Started Finished Revision Error
f08d744c-8507-478b-b971-d434309c4805 assessment-security 💥 BUG: scheduling while atomic in __synchronize_srcu 2026/06/09 21:15 2026/06/09 21:15 2026/06/09 21:34 c36c07f6c1f2230a36374cbd22235f635e8f9284 failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=arm64" "CROSS_COMPILE=aarch64-linux-gnu-" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/237275aa74063927ed19d2b56ea799a0026cd3f4" "-s" "Image.gz" "compile_commands.json"]: exit status 2 * * Restart config... * * * Kernel support for 32-bit EL0 * Kernel support for 32-bit EL0 (COMPAT) [Y/n/?] y Enable kuser helpers page for 32-bit applications (KUSER_HELPERS) [Y/n/?] y Enable vDSO for 32-bit applications (COMPAT_VDSO) [Y/n/?] (NEW) Error in reading or end of file. Compile the 32-bit vDSO for Thumb-2 mode (THUMB2_COMPAT_VDSO) [Y/n/?] (NEW) Error in reading or end of file. Fix up misaligned multi-word loads and stores in user space (COMPAT_ALIGNMENT_FIXUPS) [N/y/?] n * * ARMv8.5 architectural features * Branch Target Identification support (ARM64_BTI) [Y/n/?] y Use Branch Target Identification for kernel (ARM64_BTI_KERNEL) [Y/n/?] (NEW) Error in reading or end of file. Enable support for E0PD (ARM64_E0PD) [Y/n/?] y Memory Tagging Extension support (ARM64_MTE) [Y/n/?] y * * General architecture-dependent options * SMT (Hyperthreading) scheduler support (SCHED_SMT) [Y/n/?] y Cluster scheduler support (SCHED_CLUSTER) [Y/n/?] y Multi-Core Cache (MC) scheduler support (SCHED_MC) [Y/n/?] y Kprobes (KPROBES) [N/y/?] n Optimize very unlikely/likely branches (JUMP_LABEL) [Y/?] y Static key selftest (STATIC_KEYS_SELFTEST) [N/y/?] n Enable seccomp to safely execute untrusted bytecode (SECCOMP) [Y/n/?] y Show seccomp filter cache status in /proc/pid/seccomp_cache (SECCOMP_CACHE_DEBUG) [N/y/?] n Stack Protector buffer overflow detection (STACKPROTECTOR) [Y/n/?] y Strong Stack Protector (STACKPROTECTOR_STRONG) [Y/n/?] y Shadow Call Stack (SHADOW_CALL_STACK) [N/y/?] n Link Time Optimization (LTO) > 1. None (LTO_NONE) choice[1]: 1 Use Kernel Control Flow Integrity (kCFI) (CFI) [N/y/?] (NEW) Error in reading or end of file. Number of bits to use for ASLR of mmap base address (ARCH_MMAP_RND_BITS) [18] 18 Number of bits to use for ASLR of mmap base address for compatible applications (ARCH_MMAP_RND_COMPAT_BITS) [11] 11 MMU page size > 1. 4KiB pages (PAGE_SIZE_4KB) choice[1]: 1 Provide system calls for 32-bit time_t (COMPAT_32BIT_TIME) [Y/n/?] y Use a virtually-mapped stack (VMAP_STACK) [Y/?] y Support for randomizing kernel stack offset on syscall entry (RANDOMIZE_KSTACK_OFFSET) [Y/n/?] y Default state of kernel stack offset randomization (RANDOMIZE_KSTACK_OFFSET_DEFAULT) [N/y/?] n Locking event counts collection (LOCK_EVENT_COUNTS) [N/y/?] n * * Memory initialization * Initialize kernel stack variables at function entry 1. no automatic stack variable initialization (weakest) (INIT_STACK_NONE) 2. pattern-init everything (strongest) (INIT_STACK_ALL_PATTERN) > 3. zero-init everything (strongest and safest) (INIT_STACK_ALL_ZERO) choice[1-3?]: 3 Poison kernel stack before returning from syscalls (KSTACK_ERASE) [N/y/?] (NEW) Error in reading or end of file. Enable heap memory zeroing on allocation by default (INIT_ON_ALLOC_DEFAULT_ON) [Y/n/?] y Enable heap memory zeroing on free by default (INIT_ON_FREE_DEFAULT_ON) [N/y/?] n Enable register zeroing on function exit (ZERO_CALL_USED_REGS) [N/y/?] n * * Kernel hardening options * Randomize layout of sensitive kernel structures > 1. Disable structure layout randomization (RANDSTRUCT_NONE) 2. Fully randomize structure layout (RANDSTRUCT_FULL) (NEW) choice[1-2?]: Error in reading or end of file. aarch64-linux-gnu-objcopy: vmlinux: file format not recognized make[3]: *** [/app/workdir/cache/src/e58cb7f834f3cdf19068bc1c7f300b2f2096bc99/scripts/Makefile.vmlinux:100: vmlinux] Error 1 make[3]: *** Deleting file 'vmlinux' make[2]: *** [/app/workdir/cache/src/e58cb7f834f3cdf19068bc1c7f300b2f2096bc99/Makefile:1299: vmlinux] Error 2 make[1]: *** [/app/workdir/cache/src/e58cb7f834f3cdf19068bc1c7f300b2f2096bc99/Makefile:248: __sub-make] Error 2 make: *** [Makefile:248: __sub-make] Error 2
d919edcc-0bc4-4c21-b78f-cdc7a403ada2 assessment-security 💥 BUG: scheduling while atomic in __synchronize_srcu 2026/06/02 22:38 2026/06/02 22:38 2026/06/02 22:38 62fe15281f5011cd203d8845b8767b10e7443aa5 failed to deserialize syz repro: unknown syscall ioctl$KVM_ARM_VCPU_INIT
3d08332a-cc35-4112-b0c0-a6e6cfa8f0ad assessment-security 💥 BUG: scheduling while atomic in __synchronize_srcu 2026/05/31 01:22 2026/05/31 01:22 2026/05/31 01:22 6b4a844333e83556da95d61d7f207e7ef5cd4bc6 failed to deserialize syz repro: unknown syscall ioctl$KVM_ARM_VCPU_INIT
3cdd46b0-d977-487c-86cd-791805a779a8 assessment-security 💥 BUG: scheduling while atomic in __synchronize_srcu 2026/05/14 13:32 2026/05/14 13:32 2026/05/14 13:32 6ccb967e465e832a7bfd7a116ad00d52a0923a5d failed to deserialize syz repro: unknown syscall ioctl$KVM_ARM_VCPU_INIT
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [fuse?] BUG: scheduling while atomic in __synchronize_srcu 0 (17) 2026/04/30 18:53
[PATCH] arm64: KVM: Initialize vGIC before preempt-disabled section in kvm_reset_vcpu() 4 (4) 2026/04/21 07:42
Last patch testing requests (19)
Created Duration User Patch Repo Result
2026/04/30 18:53 56m tbsthitw@gmail.com patch upstream error
2026/04/30 18:27 20m tbsthitw@gmail.com patch upstream report log
2026/04/30 17:41 8m tbsthitw@gmail.com patch upstream error
2026/04/30 17:26 9m tbsthitw@gmail.com patch upstream error
2026/04/30 16:06 7m tbsthitw@gmail.com patch upstream error
2026/04/27 05:01 19m retest repro https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master report log
2026/04/17 10:37 0m maz@kernel.org patch upstream error
2026/04/17 07:09 0m maz@kernel.org git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git e2631e0328903f6e9711e4c253f2a855a167435b error
2026/04/16 18:22 0m maz@kernel.org git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git e2631e0328903f6e9711e4c253f2a855a167435b error
2026/04/16 18:14 0m maz@kernel.org git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git kvm-arm64/no-lazy-vgic-init error
2026/04/13 15:12 0m api-test@test.com patch upstream error
2026/04/13 15:11 0m test@test.com upstream error
2026/04/13 06:04 27m tbsthitw@gmail.com patch upstream error
2026/04/13 05:08 3h00m tbsthitw@gmail.com patch upstream error
2026/04/13 04:52 0m tbsthitw@gmail.com patch upstream error
2026/04/13 04:50 0m tbsthitw@gmail.com patch upstream error
2026/04/13 04:49 11m tbsthitw@gmail.com upstream report log
2026/04/13 04:40 0m tbsthitw@gmail.com patch upstream error
2026/04/11 05:14 36m kartikey406@gmail.com patch upstream OK log

Sample crash report:
BUG: scheduling while atomic: syz.1.49/3699/0x00000002
Modules linked in:
CPU: 1 UID: 0 PID: 3699 Comm: syz.1.49 Not tainted syzkaller #0 PREEMPT 
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace arch/arm64/kernel/stacktrace.c:498 [inline] (C)
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x60/0x80 lib/dump_stack.c:120
 dump_stack+0x18/0x24 lib/dump_stack.c:129
 __schedule_bug+0x54/0x78 kernel/sched/core.c:5847
 schedule_debug kernel/sched/core.c:5874 [inline]
 __schedule+0x858/0xd84 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0x34/0x114 kernel/sched/core.c:7008
 schedule_timeout+0xd4/0x110 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x78/0x160 kernel/sched/completion.c:153
 __synchronize_srcu+0x90/0xd0 kernel/rcu/srcutree.c:1496
 synchronize_srcu_expedited+0x24/0x40 kernel/rcu/srcutree.c:1521
 kvm_set_irq_routing+0x204/0x294 virt/kvm/irqchip.c:225
 kvm_vgic_setup_default_irq_routing+0x78/0xc0 arch/arm64/kvm/vgic/vgic-irqfd.c:153
 vgic_init+0x1ac/0x268 arch/arm64/kvm/vgic/vgic-init.c:421
 vgic_lazy_init+0x54/0x6c arch/arm64/kvm/vgic/vgic-init.c:550
 kvm_vgic_inject_irq+0x30/0x12c arch/arm64/kvm/vgic/vgic.c:520
 kvm_timer_update_irq+0x68/0x7c arch/arm64/kvm/arch_timer.c:450
 kvm_timer_vcpu_reset+0xd8/0x1e0 arch/arm64/kvm/arch_timer.c:1036
 kvm_reset_vcpu+0x194/0x360 arch/arm64/kvm/reset.c:268
 kvm_vcpu_set_target arch/arm64/kvm/arm.c:1632 [inline]
 kvm_arch_vcpu_ioctl_vcpu_init arch/arm64/kvm/arm.c:1652 [inline]
 kvm_arch_vcpu_ioctl+0x2e4/0x8c8 arch/arm64/kvm/arm.c:1773
 kvm_vcpu_ioctl+0x4ac/0x8f4 virt/kvm/kvm_main.c:4653
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __arm64_sys_ioctl+0xac/0x104 fs/ioctl.c:583
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x48/0x104 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151
 el0_svc+0x34/0x124 arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0xa0/0xf0 arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x1a4/0x1a8 arch/arm64/kernel/entry.S:596
BUG: scheduling while atomic: syz.1.49/3699/0x00000000
Modules linked in:
CPU: 1 UID: 0 PID: 3699 Comm: syz.1.49 Tainted: G        W           syzkaller #0 PREEMPT 
Tainted: [W]=WARN
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace arch/arm64/kernel/stacktrace.c:498 [inline] (C)
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x60/0x80 lib/dump_stack.c:120
 dump_stack+0x18/0x24 lib/dump_stack.c:129
 __schedule_bug+0x54/0x78 kernel/sched/core.c:5847
 schedule_debug kernel/sched/core.c:5874 [inline]
 __schedule+0x858/0xd84 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0x34/0x114 kernel/sched/core.c:7008
 futex_do_wait kernel/futex/waitwake.c:358 [inline]
 __futex_wait+0xf0/0x178 kernel/futex/waitwake.c:687
 futex_wait+0x88/0x118 kernel/futex/waitwake.c:715
 do_futex+0xf8/0x1a0 kernel/futex/syscalls.c:130
 __do_sys_futex kernel/futex/syscalls.c:207 [inline]
 __se_sys_futex kernel/futex/syscalls.c:188 [inline]
 __arm64_sys_futex+0xfc/0x1a0 kernel/futex/syscalls.c:188
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x48/0x104 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151
 el0_svc+0x34/0x124 arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0xa0/0xf0 arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x1a4/0x1a8 arch/arm64/kernel/entry.S:596
psi: inconsistent task state! task=30:pr/ttyAMA-1 cpu=1 psi_flags=14 clear=0 set=10

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/09 14:39 upstream 7f87a5ea75f0 38c8e246 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte BUG: scheduling while atomic in __synchronize_srcu
2026/04/09 12:20 upstream 7f87a5ea75f0 38c8e246 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte BUG: scheduling while atomic in __synchronize_srcu
2026/04/08 20:55 upstream 3036cd0d3328 d9b7f621 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte BUG: scheduling while atomic in __synchronize_srcu
* Struck through repros no longer work on HEAD.