Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack+0x1d/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x95/0xd0 lib/dump_stack.c:120 dump_stack+0x15/0x1b lib/dump_stack.c:129 ================================================================== BUG: KCSAN: data-race in _prb_read_valid / data_alloc write to 0xffffffff86c83408 of 8 bytes by task 2596 on cpu 1: data_alloc+0x310/0x390 kernel/printk/printk_ringbuffer.c:1129 prb_reserve+0x8d6/0xad0 kernel/printk/printk_ringbuffer.c:1727 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 fserror_report+0x427/0x500 fs/fserror.c:182 fserror_report_metadata include/linux/fserror.h:67 [inline] __ext4_std_error+0x15f/0x350 fs/ext4/super.c:978 ext4_process_orphan+0x14e/0x1c0 fs/ext4/orphan.c:345 ext4_orphan_cleanup+0x69c/0x9f0 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5701 [inline] ext4_fill_super+0x3408/0x37c0 fs/ext4/super.c:5824 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694 get_tree_bdev+0x1f/0x30 fs/super.c:1717 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5856 vfs_get_tree+0x57/0x1d0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x288/0x8d0 fs/namespace.c:3834 path_mount+0x4d0/0xbc0 fs/namespace.c:4154 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4360 __x64_sys_mount+0x67/0x80 fs/namespace.c:4360 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff86c83408 of 16 bytes by task 2614 on cpu 0: desc_read kernel/printk/printk_ringbuffer.c:496 [inline] desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1934 [inline] prb_read kernel/printk/printk_ringbuffer.c:1982 [inline] _prb_read_valid+0x1b6/0x950 kernel/printk/printk_ringbuffer.c:2173 desc_update_last_finalized+0x8f/0x170 kernel/printk/printk_ringbuffer.c:1573 prb_final_commit+0x111/0x150 kernel/printk/printk_ringbuffer.c:1842 vprintk_store+0x88b/0x910 kernel/printk/printk.c:2381 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 printk_stack_address arch/x86/kernel/dumpstack.c:70 [inline] __show_trace_log_lvl+0x460/0x560 arch/x86/kernel/dumpstack.c:282 __dump_stack+0x1d/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x95/0xd0 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+0x263/0x280 lib/fault-inject.c:174 should_fail+0xb/0x20 lib/fault-inject.c:184 should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:35 _inline_copy_from_user include/linux/uaccess.h:170 [inline] _copy_from_user+0x1c/0xb0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:223 [inline] copy_from_sockptr_offset include/linux/sockptr.h:48 [inline] copy_from_sockptr+0x48/0x70 include/linux/sockptr.h:61 ip_mroute_setsockopt+0x615/0xa00 net/ipv4/ipmr.c:1507 do_ip_setsockopt+0xcea/0x2290 net/ipv4/ip_sockglue.c:948 ip_setsockopt+0x58/0x110 net/ipv4/ip_sockglue.c:1417 raw_setsockopt+0xbd/0x150 net/ipv4/raw.c:849 sock_common_setsockopt+0x69/0x80 net/core/sock.c:3989 do_sock_setsockopt net/socket.c:2381 [inline] __sys_setsockopt+0x184/0x200 net/socket.c:2406 __do_sys_setsockopt net/socket.c:2412 [inline] __se_sys_setsockopt net/socket.c:2409 [inline] __x64_sys_setsockopt+0x64/0x80 net/socket.c:2409 x64_sys_call+0x2327/0x3020 arch/x86/include/generated/asm/syscalls_64.h:55 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 2614 Comm: syz.1.6780 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 ================================================================== fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x263/0x280 lib/fault-inject.c:174 should_fail+0xb/0x20 lib/fault-inject.c:184 should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:35 _inline_copy_from_user include/linux/uaccess.h:170 [inline] _copy_from_user+0x1c/0xb0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:223 [inline] copy_from_sockptr_offset include/linux/sockptr.h:48 [inline] copy_from_sockptr+0x48/0x70 include/linux/sockptr.h:61 ip_mroute_setsockopt+0x615/0xa00 net/ipv4/ipmr.c:1507 do_ip_setsockopt+0xcea/0x2290 net/ipv4/ip_sockglue.c:948 ip_setsockopt+0x58/0x110 net/ipv4/ip_sockglue.c:1417 raw_setsockopt+0xbd/0x150 net/ipv4/raw.c:849 sock_common_setsockopt+0x69/0x80 net/core/sock.c:3989 do_sock_setsockopt net/socket.c:2381 [inline] __sys_setsockopt+0x184/0x200 net/socket.c:2406 __do_sys_setsockopt net/socket.c:2412 [inline] __se_sys_setsockopt net/socket.c:2409 [inline] __x64_sys_setsockopt+0x64/0x80 net/socket.c:2409 x64_sys_call+0x2327/0x3020 arch/x86/include/generated/asm/syscalls_64.h:55 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2baaa4ce59 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:00007f2ba9486028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f2baacc6090 RCX: 00007f2baaa4ce59 RDX: 00000000000000d2 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f2ba9486090 R08: 000000000000003c R09: 0000000000000000 R10: 0000200000000040 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f2baacc6128 R14: 00007f2baacc6090 R15: 00007ffd95caa5c8