strncpy_from_bpfptr+0x38/0x60 include/linux/bpfptr.h:86 bpf_prog_load+0x868/0x1070 kernel/bpf/syscall.c:2849 __sys_bpf+0x463/0x7a0 kernel/bpf/syscall.c:5710 ================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff86675158 of 8 bytes by task 12800 on cpu 1: data_alloc+0x291/0x2c0 kernel/printk/printk_ringbuffer.c:1096 prb_reserve+0x85e/0xb60 kernel/printk/printk_ringbuffer.c:1669 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2269 vprintk_emit+0x13a/0x610 kernel/printk/printk.c:2329 vprintk_default+0x26/0x30 kernel/printk/printk.c:2363 vprintk+0x75/0x80 kernel/printk/printk_safe.c:45 _printk+0x7a/0xa0 kernel/printk/printk.c:2373 __netdev_printk+0x2d1/0x3e0 net/core/dev.c:11770 netdev_info+0x99/0xc0 net/core/dev.c:11817 __dev_set_promiscuity+0x165/0x340 net/core/dev.c:8627 __dev_change_flags+0x1ed/0x410 net/core/dev.c:8847 dev_change_flags+0x59/0xd0 net/core/dev.c:8910 devinet_ioctl+0x587/0xef0 net/ipv4/devinet.c:1177 inet_ioctl+0x2f4/0x3a0 net/ipv4/af_inet.c:1003 sock_do_ioctl+0x81/0x260 net/socket.c:1222 sock_ioctl+0x470/0x640 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xd3/0x150 fs/ioctl.c:893 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893 x64_sys_call+0x15cc/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff86675158 of 8 bytes by task 12795 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+0x235/0xb60 kernel/printk/printk_ringbuffer.c:1619 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2269 vprintk_emit+0x13a/0x610 kernel/printk/printk.c:2329 vprintk_default+0x26/0x30 kernel/printk/printk.c:2363 vprintk+0x75/0x80 kernel/printk/printk_safe.c:45 _printk+0x7a/0xa0 kernel/printk/printk.c:2373 printk_stack_address arch/x86/kernel/dumpstack.c:72 [inline] show_trace_log_lvl+0x430/0x510 arch/x86/kernel/dumpstack.c:285 __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0xf2/0x150 lib/dump_stack.c:119 dump_stack+0x15/0x20 lib/dump_stack.c:128 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x229/0x230 lib/fault-inject.c:153 should_fail+0xb/0x10 lib/fault-inject.c:163 should_fail_usercopy+0x1a/0x20 lib/fault-inject-usercopy.c:37 strncpy_from_user+0x25/0x270 lib/strncpy_from_user.c:118 strncpy_from_bpfptr+0x38/0x60 include/linux/bpfptr.h:86 bpf_prog_load+0x868/0x1070 kernel/bpf/syscall.c:2849 __sys_bpf+0x463/0x7a0 kernel/bpf/syscall.c:5710 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5815 x64_sys_call+0x2625/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0xffffffffffff3348 -> 0x000000000008c8a0 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 12795 Comm: syz.1.3095 Not tainted 6.11.0-rc5-syzkaller-00081-gd5d547aa7b51 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 ================================================================== __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5815 x64_sys_call+0x2625/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f11be7d9ef9 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:00007f11bd457038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f11be975f80 RCX: 00007f11be7d9ef9 RDX: 0000000000000090 RSI: 0000000020000440 RDI: 0000000000000005 RBP: 00007f11bd457090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f11be975f80 R15: 00007ffc92edd2c8