ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3d2606654f RDX: 0000000000000001 RSI: 00007f3d23e091e0 RDI: 0000000000000004 ================================================================== BUG: KCSAN: data-race in data_push_tail / vsnprintf write to 0xffffffff84141498 of 1 bytes by task 870 on cpu 0: vsnprintf+0xe8f/0xed0 vscnprintf+0x29/0x80 lib/vsprintf.c:2900 printk_sprint kernel/printk/printk.c:2075 [inline] vprintk_store+0x4a6/0xb80 kernel/printk/printk.c:2153 vprintk_emit+0xac/0x390 kernel/printk/printk.c:2228 vprintk_default+0x22/0x30 kernel/printk/printk.c:2255 vprintk+0x7f/0x90 kernel/printk/printk_safe.c:50 _printk+0x76/0x97 kernel/printk/printk.c:2265 show_free_areas+0x8f0/0x9f0 mm/page_alloc.c:6052 show_mem+0x2a/0x1f0 lib/show_mem.c:17 warn_alloc_show_mem mm/page_alloc.c:4202 [inline] warn_alloc+0x182/0x190 mm/page_alloc.c:4225 __vmalloc_node_range+0x207/0x600 __vmalloc_node mm/vmalloc.c:3069 [inline] __vmalloc+0x5a/0x70 mm/vmalloc.c:3083 bpf_prog_alloc_no_stats+0x33/0x200 kernel/bpf/core.c:87 bpf_prog_alloc+0x16/0xe0 kernel/bpf/core.c:121 bpf_prog_create_from_user+0x6f/0x240 net/core/filter.c:1414 seccomp_prepare_filter kernel/seccomp.c:666 [inline] seccomp_prepare_user_filter kernel/seccomp.c:703 [inline] seccomp_set_mode_filter kernel/seccomp.c:1824 [inline] do_seccomp+0x5ec/0x1590 kernel/seccomp.c:1944 __do_sys_seccomp kernel/seccomp.c:1963 [inline] __se_sys_seccomp kernel/seccomp.c:1960 [inline] __x64_sys_seccomp+0x3c/0x50 kernel/seccomp.c:1960 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 read to 0xffffffff84141498 of 8 bytes by task 890 on cpu 1: data_make_reusable kernel/printk/printk_ringbuffer.c:587 [inline] data_push_tail+0x138/0x470 kernel/printk/printk_ringbuffer.c:672 data_alloc+0xbc/0x2b0 kernel/printk/printk_ringbuffer.c:1043 prb_reserve+0x920/0xbf0 kernel/printk/printk_ringbuffer.c:1549 vprintk_store+0x53a/0xb80 kernel/printk/printk.c:2175 vprintk_emit+0xac/0x390 kernel/printk/printk.c:2228 vprintk_default+0x22/0x30 kernel/printk/printk.c:2255 vprintk+0x7f/0x90 kernel/printk/printk_safe.c:50 _printk+0x76/0x97 kernel/printk/printk.c:2265 __show_regs+0x80/0x330 arch/x86/kernel/process_64.c:83 show_regs_if_on_stack arch/x86/kernel/dumpstack.c:173 [inline] show_trace_log_lvl+0x5b8/0x670 arch/x86/kernel/dumpstack.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd6/0x122 lib/dump_stack.c:106 dump_stack+0x11/0x1b lib/dump_stack.c:113 fail_dump lib/fault-inject.c:52 [inline] should_fail+0x23c/0x250 lib/fault-inject.c:146 should_fail_usercopy+0x16/0x20 lib/fault-inject-usercopy.c:37 _copy_from_user+0x1c/0xd0 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:192 [inline] kstrtouint_from_user+0x7e/0x170 lib/kstrtox.c:410 proc_fail_nth_write+0x4b/0x150 fs/proc/base.c:1398 vfs_write+0x286/0x900 fs/read_write.c:592 ksys_write+0xd9/0x190 fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:656 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: 0x0000000100000444 -> 0x426b36312a342029 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 890 Comm: syz-executor.3 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== RBP: 00007f3d23e091d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffc7d428f2f R14: 00007f3d23e09300 R15: 0000000000022000