FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 CPU: 0 UID: 0 PID: 22884 Comm: syz.2.6898 Tainted: G W syzkaller #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __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_fail+0xb/0x20 lib/fault-inject.c:184 ================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff868967f0 of 8 bytes by task 22879 on cpu 1: data_alloc+0x27d/0x2b0 kernel/printk/printk_ringbuffer.c:1096 prb_reserve+0x808/0xaf0 kernel/printk/printk_ringbuffer.c:1669 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2475 rock_continue+0x2d2/0x2e0 fs/isofs/rock.c:127 parse_rock_ridge_inode_internal+0xf44/0x1030 fs/isofs/rock.c:592 parse_rock_ridge_inode+0x3d/0xe0 fs/isofs/rock.c:677 isofs_read_inode fs/isofs/inode.c:1408 [inline] __isofs_iget+0xb9b/0x1100 fs/isofs/inode.c:1519 isofs_iget fs/isofs/isofs.h:135 [inline] isofs_fill_super+0xd66/0x1270 fs/isofs/inode.c:864 get_tree_bdev_flags+0x28e/0x300 fs/super.c:1692 get_tree_bdev+0x1f/0x30 fs/super.c:1715 isofs_get_tree+0x1c/0x30 fs/isofs/inode.c:1533 vfs_get_tree+0x57/0x1d0 fs/super.c:1815 do_new_mount+0x207/0x5e0 fs/namespace.c:3808 path_mount+0x4a4/0xb20 fs/namespace.c:4123 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4324 __x64_sys_mount+0x67/0x80 fs/namespace.c:4324 x64_sys_call+0x2b4d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff868967f0 of 8 bytes by task 22884 on cpu 0: desc_read kernel/printk/printk_ringbuffer.c:482 [inline] desc_push_tail kernel/printk/printk_ringbuffer.c:778 [inline] desc_reserve kernel/printk/printk_ringbuffer.c:924 [inline] prb_reserve+0x221/0xaf0 kernel/printk/printk_ringbuffer.c:1619 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2475 printk_stack_address arch/x86/kernel/dumpstack.c:70 [inline] show_trace_log_lvl+0x4e3/0x560 arch/x86/kernel/dumpstack.c:282 __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_fail+0xb/0x20 lib/fault-inject.c:184 should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:37 _inline_copy_from_user include/linux/uaccess.h:163 [inline] _copy_from_user+0x1c/0xb0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] copy_msghdr_from_user net/socket.c:2544 [inline] sendmsg_copy_msghdr net/socket.c:2645 [inline] ___sys_sendmsg+0xc1/0x1d0 net/socket.c:2664 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2703 x64_sys_call+0x191e/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000000000665b0 -> 0x0000000000103828 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 22884 Comm: syz.2.6898 Tainted: G W syzkaller #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 ================================================================== should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:37 _inline_copy_from_user include/linux/uaccess.h:163 [inline] _copy_from_user+0x1c/0xb0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] copy_msghdr_from_user net/socket.c:2544 [inline] sendmsg_copy_msghdr net/socket.c:2645 [inline] ___sys_sendmsg+0xc1/0x1d0 net/socket.c:2664 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2703 x64_sys_call+0x191e/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4681e1eec9 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:00007f4680887038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4682075fa0 RCX: 00007f4681e1eec9 RDX: 0000000000040006 RSI: 0000200000000700 RDI: 0000000000000003 RBP: 00007f4680887090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f4682076038 R14: 00007f4682075fa0 R15: 00007ffd8cd60ff8