================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596 Read of size 4 at addr ffff8880662268d0 by task syz-executor.1/3855 CPU: 1 PID: 3855 Comm: syz-executor.1 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x17 mm/kasan/common.c:618 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131 tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline] tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596 tcp_write_timer+0xa8/0x1e0 net/ipv4/tcp_timer.c:612 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698 __do_softirq+0x262/0x98c kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:337 do_softirq kernel/softirq.c:329 [inline] __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:189 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:681 [inline] ip6_finish_output2+0x10a0/0x2520 net/ipv6/ip6_output.c:117 __ip6_finish_output+0x444/0xa50 net/ipv6/ip6_output.c:142 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x235/0x7c0 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] ip6_local_out+0xbb/0x184 net/ipv6/output_core.c:179 ip6_send_skb+0xbb/0x300 net/ipv6/ip6_output.c:1791 udp_v6_send_skb.isra.0+0x839/0x14c0 net/ipv6/udp.c:1167 udpv6_sendmsg+0x21dc/0x2990 net/ipv6/udp.c:1464 inet6_sendmsg+0x9e/0xe0 net/ipv6/af_inet6.c:576 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:657 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459879 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f83abd75c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459879 RDX: 00000000000004ff RSI: 00000000200092c0 RDI: 0000000000000004 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f83abd766d4 R13: 00000000004c706e R14: 00000000004dc6e8 R15: 00000000ffffffff Allocated by task 3639: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:493 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:466 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:507 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3550 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:748 [inline] tomoyo_find_next_domain+0x126/0x1f6c security/tomoyo/domain.c:712 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:107 [inline] tomoyo_bprm_check_security+0x124/0x1b0 security/tomoyo/tomoyo.c:97 security_bprm_check+0x63/0xb0 security/security.c:750 search_binary_handler+0x71/0x570 fs/exec.c:1645 exec_binprm fs/exec.c:1701 [inline] __do_execve_file.isra.0+0x1333/0x2340 fs/exec.c:1821 do_execveat_common fs/exec.c:1868 [inline] do_execve+0x33/0x40 fs/exec.c:1885 call_usermodehelper_exec_async+0x5a4/0x730 kernel/umh.c:112 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 3639: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:455 kasan_slab_free+0xe/0x10 mm/kasan/common.c:463 __cache_free mm/slab.c:3425 [inline] kfree+0x10a/0x2c0 mm/slab.c:3756 tomoyo_find_next_domain+0x72f/0x1f6c security/tomoyo/domain.c:878 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:107 [inline] tomoyo_bprm_check_security+0x124/0x1b0 security/tomoyo/tomoyo.c:97 security_bprm_check+0x63/0xb0 security/security.c:750 search_binary_handler+0x71/0x570 fs/exec.c:1645 exec_binprm fs/exec.c:1701 [inline] __do_execve_file.isra.0+0x1333/0x2340 fs/exec.c:1821 do_execveat_common fs/exec.c:1868 [inline] do_execve+0x33/0x40 fs/exec.c:1885 call_usermodehelper_exec_async+0x5a4/0x730 kernel/umh.c:112 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff888066226040 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2192 bytes inside of 4096-byte region [ffff888066226040, ffff888066227040) The buggy address belongs to the page: page:ffffea0001988980 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002218a08 ffffea00026b8988 ffff8880aa402000 raw: 0000000000000000 ffff888066226040 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888066226780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888066226800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888066226880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888066226900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888066226980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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