BUG: KCSAN: data-race in data_push_tail / vsnprintf write to 0xffffffff86dc6af8 of 1 bytes by task 29647 on cpu 0: vsnprintf+0xe8f/0xed0 vscnprintf+0x29/0x80 lib/vsprintf.c:2908 printk_sprint kernel/printk/printk.c:2075 [inline] vprintk_store+0x638/0xbb0 kernel/printk/printk.c:2185 vprintk_emit+0xac/0x3c0 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 logfc+0x2f4/0x300 get_tree_bdev+0xc4/0x3d0 fs/super.c:1247 vfs_get_tree+0x4a/0x1a0 fs/super.c:1500 do_new_mount fs/namespace.c:2994 [inline] path_mount+0x11cf/0x1c40 fs/namespace.c:3324 do_mount fs/namespace.c:3337 [inline] __do_sys_mount fs/namespace.c:3545 [inline] __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3522 __x64_sys_mount+0x63/0x70 fs/namespace.c:3522 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffffffff86dc6af8 of 8 bytes by task 29610 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+0x560/0xbb0 kernel/printk/printk.c:2175 vprintk_emit+0xac/0x3c0 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 printk_stack_address arch/x86/kernel/dumpstack.c:72 [inline] show_trace_log_lvl+0x5f7/0x670 arch/x86/kernel/dumpstack.c:282 __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_failslab+0x81/0x90 mm/failslab.c:33 should_failslab+0x5/0x20 mm/slab_common.c:1320 slab_pre_alloc_hook mm/slab.h:713 [inline] slab_alloc mm/slab.c:3298 [inline] kmem_cache_alloc_trace+0x52/0x350 mm/slab.c:3565 kmalloc include/linux/slab.h:582 [inline] kzalloc include/linux/slab.h:716 [inline] alloc_fs_context+0x46/0x500 fs/fs_context.c:257 fs_context_for_mount+0x1d/0x20 fs/fs_context.c:304 do_new_mount fs/namespace.c:2979 [inline] path_mount+0xdf0/0x1c40 fs/namespace.c:3324 do_mount fs/namespace.c:3337 [inline] __do_sys_mount fs/namespace.c:3545 [inline] __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3522 __x64_sys_mount+0x63/0x70 fs/namespace.c:3522 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000000100001ee3 -> 0x0000000100001e00 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 29610 Comm: syz-executor.1 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== kmalloc include/linux/slab.h:582 [inline] kzalloc include/linux/slab.h:716 [inline] alloc_fs_context+0x46/0x500 fs/fs_context.c:257 fs_context_for_mount+0x1d/0x20 fs/fs_context.c:304 do_new_mount fs/namespace.c:2979 [inline] path_mount+0xdf0/0x1c40 fs/namespace.c:3324 do_mount fs/namespace.c:3337 [inline] __do_sys_mount fs/namespace.c:3545 [inline] __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3522 __x64_sys_mount+0x63/0x70 fs/namespace.c:3522 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f3422005eb9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f342117c168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f3422118f60 RCX: 00007f3422005eb9 RDX: 00000000200001c0 RSI: 0000000020000180 RDI: 0000000020000200 RBP: 00007f342117c1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fffae0c568f R14: 00007f342117c300 R15: 0000000000022000