================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff86068f68 of 8 bytes by task 14645 on cpu 0: 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+0x10c/0x5e0 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 batadv_check_known_mac_addr+0x147/0x180 net/batman-adv/hard-interface.c:526 batadv_hard_if_event+0x4b0/0x1000 net/batman-adv/hard-interface.c:998 notifier_call_chain kernel/notifier.c:93 [inline] raw_notifier_call_chain+0x6f/0x1d0 kernel/notifier.c:461 call_netdevice_notifiers_info+0xae/0x100 net/core/dev.c:1992 call_netdevice_notifiers_extack net/core/dev.c:2030 [inline] call_netdevice_notifiers net/core/dev.c:2044 [inline] dev_set_mac_address+0x1ff/0x260 net/core/dev.c:9044 dev_set_mac_address_user+0x31/0x50 net/core/dev.c:9058 do_setlink+0x510/0x2490 net/core/rtnetlink.c:2855 __rtnl_newlink net/core/rtnetlink.c:3696 [inline] rtnl_newlink+0x11a1/0x1690 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x85e/0x910 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x12c/0x230 net/netlink/af_netlink.c:2564 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6653 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x58d/0x660 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x5ca/0x6e0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x140/0x180 net/socket.c:745 __sys_sendto+0x1e5/0x260 net/socket.c:2192 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2200 x64_sys_call+0x16d7/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:45 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 0xffffffff86068f68 of 8 bytes by task 14827 on cpu 1: 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+0x10c/0x5e0 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:88 [inline] dump_stack_lvl+0xf2/0x150 lib/dump_stack.c:114 dump_stack+0x15/0x20 lib/dump_stack.c:123 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x229/0x230 lib/fault-inject.c:153 __should_failslab+0x92/0xa0 mm/failslab.c:44 should_failslab+0x9/0x20 mm/slub.c:3880 slab_pre_alloc_hook mm/slub.c:3893 [inline] slab_alloc_node mm/slub.c:3982 [inline] kmem_cache_alloc_node_noprof+0x51/0x2b0 mm/slub.c:4045 __alloc_skb+0x10b/0x300 net/core/skbuff.c:656 alloc_skb include/linux/skbuff.h:1308 [inline] netlink_alloc_large_skb+0xad/0xe0 net/netlink/af_netlink.c:1210 netlink_sendmsg+0x3b4/0x6e0 net/netlink/af_netlink.c:1880 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x140/0x180 net/socket.c:745 __sys_sendto+0x1e5/0x260 net/socket.c:2192 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2200 x64_sys_call+0x16d7/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:45 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: 0xfffffffffffd1868 -> 0x000000000007c3b8 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 14827 Comm: syz.4.3254 Not tainted 6.10.0-rc6-syzkaller-00212-g1dd28064d416 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 ================================================================== __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xf2/0x150 lib/dump_stack.c:114 dump_stack+0x15/0x20 lib/dump_stack.c:123 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x229/0x230 lib/fault-inject.c:153 __should_failslab+0x92/0xa0 mm/failslab.c:44 should_failslab+0x9/0x20 mm/slub.c:3880 slab_pre_alloc_hook mm/slub.c:3893 [inline] slab_alloc_node mm/slub.c:3982 [inline] kmem_cache_alloc_node_noprof+0x51/0x2b0 mm/slub.c:4045 __alloc_skb+0x10b/0x300 net/core/skbuff.c:656 alloc_skb include/linux/skbuff.h:1308 [inline] netlink_alloc_large_skb+0xad/0xe0 net/netlink/af_netlink.c:1210 netlink_sendmsg+0x3b4/0x6e0 net/netlink/af_netlink.c:1880 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x140/0x180 net/socket.c:745 __sys_sendto+0x1e5/0x260 net/socket.c:2192 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2200 x64_sys_call+0x16d7/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:45 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: 0033:0x7f2ca987196c Code: 2a 5a 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5a 02 00 48 8b RSP: 002b:00007f2ca8aefed0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f2ca8aeffd0 RCX: 00007f2ca987196c RDX: 0000000000000024 RSI: 00007f2ca8af0020 RDI: 0000000000000006 RBP: 0000000000000000 R08: 00007f2ca8aeff24 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000006 R13: 00007f2ca8aeff78 R14: 00007f2ca8af0020 R15: 0000000000000000