================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 Read of size 8 at addr ffff888077bdd540 by task kworker/u4:7/4393 CPU: 1 PID: 4393 Comm: kworker/u4:7 Not tainted 5.18.0-rc3-syzkaller-01632-gc272e2591169 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511 tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:200 Code: 4b 00 5d be 03 00 00 00 e9 16 be 7e 02 66 0f 1f 44 00 00 48 8b be a8 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 59 42 89 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 RSP: 0000:ffffc90013647c80 EFLAGS: 00000293 RAX: 0000000080000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff890874ce RDI: ffff88805bccbe3c RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff890874c1 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000062 rcu_lock_release include/linux/rcupdate.h:273 [inline] rcu_read_unlock include/linux/rcupdate.h:727 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x858/0xfa0 net/batman-adv/network-coding.c:719 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 3623: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:749 [inline] slab_alloc_node mm/slub.c:3217 [inline] slab_alloc mm/slub.c:3225 [inline] __kmem_cache_alloc_lru mm/slub.c:3232 [inline] kmem_cache_alloc+0x204/0x3b0 mm/slub.c:3242 kmem_cache_zalloc include/linux/slab.h:704 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3132 __do_sys_unshare kernel/fork.c:3203 [inline] __se_sys_unshare kernel/fork.c:3201 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3201 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x62e/0x1140 kernel/workqueue.c:1517 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1461 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1752 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x62e/0x1140 kernel/workqueue.c:1517 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1461 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1752 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 The buggy address belongs to the object at ffff888077bdd280 which belongs to the cache net_namespace of size 6784 The buggy address is located 704 bytes inside of 6784-byte region [ffff888077bdd280, ffff888077bded00) The buggy address belongs to the physical page: page:ffffea0001def600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888077bdd280 pfn:0x77bd8 head:ffffea0001def600 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88806461f1c1 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00010dee08 ffff888010dce288 ffff888010dcd3c0 raw: ffff888077bdd280 0000000000040001 00000001ffffffff ffff88806461f1c1 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3621, tgid 3621 (syz-executor.1), ts 99347450934, free_ts 99346285092 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0x8df/0xf20 mm/slub.c:3005 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092 slab_alloc_node mm/slub.c:3183 [inline] slab_alloc mm/slub.c:3225 [inline] __kmem_cache_alloc_lru mm/slub.c:3232 [inline] kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3242 kmem_cache_zalloc include/linux/slab.h:704 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3132 __do_sys_unshare kernel/fork.c:3203 [inline] __se_sys_unshare kernel/fork.c:3201 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3201 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3328 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423 skb_free_head+0xac/0x110 net/core/skbuff.c:655 skb_release_data+0x67a/0x810 net/core/skbuff.c:677 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb net/core/skbuff.c:756 [inline] consume_skb net/core/skbuff.c:915 [inline] consume_skb+0xc2/0x160 net/core/skbuff.c:909 skb_free_datagram+0x1b/0x1f0 net/core/datagram.c:324 netlink_recvmsg+0x61a/0xea0 net/netlink/af_netlink.c:1999 sock_recvmsg_nosec net/socket.c:948 [inline] sock_recvmsg net/socket.c:966 [inline] sock_recvmsg net/socket.c:962 [inline] ____sys_recvmsg+0x2be/0x5f0 net/socket.c:2632 ___sys_recvmsg+0x127/0x200 net/socket.c:2674 __sys_recvmsg+0xe2/0x1a0 net/socket.c:2704 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888077bdd400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888077bdd480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888077bdd500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888077bdd580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888077bdd600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 4b 00 5d be rex.WXB add %bl,-0x42(%r13) 4: 03 00 add (%rax),%eax 6: 00 00 add %al,(%rax) 8: e9 16 be 7e 02 jmpq 0x27ebe23 d: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 13: 48 8b be a8 01 00 00 mov 0x1a8(%rsi),%rdi 1a: e8 b4 ff ff ff callq 0xffffffd3 1f: 31 c0 xor %eax,%eax 21: c3 retq 22: 90 nop 23: 65 8b 05 59 42 89 7e mov %gs:0x7e894259(%rip),%eax # 0x7e894283 * 2a: 89 c1 mov %eax,%ecx <-- trapping instruction 2c: 48 8b 34 24 mov (%rsp),%rsi 30: 81 e1 00 01 00 00 and $0x100,%ecx 36: 65 48 8b 14 25 00 70 mov %gs:0x27000,%rdx 3d: 02 00 3f: a9 .byte 0xa9