seccomp_log kernel/seccomp.c:1048 [inline] __seccomp_filter+0x843/0x1260 kernel/seccomp.c:1344 __secure_computing+0x82/0x150 kernel/seccomp.c:1404 syscall_trace_enter+0xcf/0x1e0 kernel/entry/syscall-common.c:44 syscall_enter_from_user_mode_work include/linux/entry-common.h:78 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:109 [inline] do_syscall_64+0xb2/0x2a0 arch/x86/entry/syscall_64.c:90 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f891b3bf749 ================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff8687d470 of 8 bytes by task 29478 on cpu 1: data_alloc+0x31c/0x390 kernel/printk/printk_ringbuffer.c:1130 prb_reserve+0x964/0xb60 kernel/printk/printk_ringbuffer.c:1724 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2302 vprintk_emit+0x15a/0x610 kernel/printk/printk.c:2402 vprintk_default+0x26/0x30 kernel/printk/printk.c:2441 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2451 find_valid_gpt block/partitions/efi.c:-1 [inline] efi_partition+0x12bd/0x1400 block/partitions/efi.c:719 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x4b9/0xcb0 block/partitions/core.c:693 loop_reread_partitions drivers/block/loop.c:449 [inline] loop_set_status+0x5d2/0x6a0 drivers/block/loop.c:1278 loop_set_status64 drivers/block/loop.c:1374 [inline] lo_ioctl+0x671/0x12b0 drivers/block/loop.c:1560 blkdev_ioctl+0x37d/0x460 block/ioctl.c:707 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583 x64_sys_call+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd8/0x2a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff8687d470 of 8 bytes by task 29484 on cpu 0: desc_read kernel/printk/printk_ringbuffer.c:496 [inline] desc_push_tail kernel/printk/printk_ringbuffer.c:792 [inline] desc_reserve kernel/printk/printk_ringbuffer.c:938 [inline] prb_reserve+0x249/0xb60 kernel/printk/printk_ringbuffer.c:1674 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2302 vprintk_emit+0x15a/0x610 kernel/printk/printk.c:2402 vprintk_default+0x26/0x30 kernel/printk/printk.c:2441 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2451 show_opcodes+0xfe/0x120 arch/x86/kernel/dumpstack.c:121 show_iret_regs+0x12/0x40 arch/x86/kernel/dumpstack.c:147 __show_regs+0x2a/0x440 arch/x86/kernel/process_64.c:78 show_regs_if_on_stack arch/x86/kernel/dumpstack.c:165 [inline] __show_trace_log_lvl+0x423/0x560 arch/x86/kernel/dumpstack.c:298 __dump_stack+0x1d/0x30 lib/dump_stack.c:94 dump_stack_lvl+0xe8/0x140 lib/dump_stack.c:120 dump_stack+0x15/0x1b lib/dump_stack.c:129 fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x265/0x280 lib/fault-inject.c:174 should_failslab+0x8c/0xb0 mm/failslab.c:46 slab_pre_alloc_hook mm/slub.c:4901 [inline] slab_alloc_node mm/slub.c:5234 [inline] __do_kmalloc_node mm/slub.c:5651 [inline] __kmalloc_node_track_caller_noprof+0xb9/0x5b0 mm/slub.c:5759 kmemdup_noprof+0x2b/0x70 mm/util.c:138 kmemdup_noprof include/linux/fortify-string.h:765 [inline] sidtab_sid2str_get+0xa0/0x130 security/selinux/ss/sidtab.c:625 sidtab_entry_to_string security/selinux/ss/services.c:1316 [inline] security_sid_to_context_core+0x1eb/0x2e0 security/selinux/ss/services.c:1419 security_sid_to_context+0x27/0x40 security/selinux/ss/services.c:1440 selinux_secid_to_secctx security/selinux/hooks.c:6823 [inline] selinux_lsmprop_to_secctx+0x67/0xf0 security/selinux/hooks.c:6837 security_lsmprop_to_secctx+0x1a3/0x1c0 security/security.c:3859 audit_log_subj_ctx+0xa4/0x3e0 kernel/audit.c:2294 audit_log_task_context+0x48/0x70 kernel/audit.c:2344 audit_log_task+0xf4/0x250 kernel/auditsc.c:2924 audit_seccomp+0x61/0x100 kernel/auditsc.c:2974 seccomp_log kernel/seccomp.c:1048 [inline] __seccomp_filter+0x843/0x1260 kernel/seccomp.c:1344 __secure_computing+0x82/0x150 kernel/seccomp.c:1404 syscall_trace_enter+0xcf/0x1e0 kernel/entry/syscall-common.c:44 syscall_enter_from_user_mode_work include/linux/entry-common.h:78 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:109 [inline] do_syscall_64+0xb2/0x2a0 arch/x86/entry/syscall_64.c:90 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000000000aca28 -> 0x000000000014eb40 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 29484 Comm: syz.8.9648 Tainted: G W syzkaller #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 ================================================================== Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8919e1f038 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab RAX: ffffffffffffffda RBX: 00007f891b615fa0 RCX: 00007f891b3bf749 RDX: 0000200000000080 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f8919e1f090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f891b616038 R14: 00007f891b615fa0 R15: 00007ffd4dba45d8 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: ff c3 inc %ebx 2: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 9: 00 00 00 c: 0f 1f 40 00 nopl 0x0(%rax) 10: 48 89 f8 mov %rdi,%rax 13: 48 89 f7 mov %rsi,%rdi 16: 48 89 d6 mov %rdx,%rsi 19: 48 89 ca mov %rcx,%rdx 1c: 4d 89 c2 mov %r8,%r10 1f: 4d 89 c8 mov %r9,%r8 22: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 27: 0f 05 syscall * 29: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 2f: 73 01 jae 0x32 31: c3 ret 32: 48 c7 c1 a8 ff ff ff mov $0xffffffffffffffa8,%rcx 39: f7 d8 neg %eax 3b: 64 89 01 mov %eax,%fs:(%rcx) 3e: 48 rex.W