================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6df/0x2810 net/ipv4/tcp_timer.c:531 Read of size 8 at addr ffff888078900258 by task udevd/6622 CPU: 0 PID: 6622 Comm: udevd Not tainted 5.15.146-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 tcp_retransmit_timer+0x6df/0x2810 net/ipv4/tcp_timer.c:531 tcp_write_timer_handler+0x1f7/0x9c0 net/ipv4/tcp_timer.c:644 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:664 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:unwind_next_frame+0x142d/0x1fa0 arch/x86/kernel/unwind_orc.c:616 Code: 00 80 3b 00 0f 85 85 02 00 00 80 3d 84 d3 97 0c 00 0f 85 78 02 00 00 c6 05 77 d3 97 0c 01 48 c7 c7 c0 7d 88 8a e9 0e fa ff ff 01 00 00 00 e8 09 bb 1e 00 65 8b 0d aa f3 c9 7e b0 01 85 c9 0f RSP: 0018:ffffc90002f37368 EFLAGS: 00000206 RAX: ffffc90002f38000 RBX: ffffc90002f37430 RCX: ffffc90002f37e48 RDX: dffffc0000000000 RSI: ffffc90002f37e30 RDI: ffffc90002f37428 RBP: ffffc90002f37e40 R08: ffffc90002f37e30 R09: ffffc90002f37470 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1cc8327 R13: 1ffffffff1cc8327 R14: ffffc90002f30000 R15: ffffc90002f37420 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] lsm_file_alloc security/security.c:574 [inline] security_file_alloc+0x24/0x120 security/security.c:1530 __alloc_file+0xc3/0x240 fs/file_table.c:106 alloc_empty_file+0x92/0x180 fs/file_table.c:150 path_openat+0xfc/0x2f20 fs/namei.c:3734 do_filp_open+0x21c/0x460 fs/namei.c:3775 do_sys_openat2+0x13b/0x500 fs/open.c:1211 do_sys_open fs/open.c:1227 [inline] __do_sys_openat fs/open.c:1243 [inline] __se_sys_openat fs/open.c:1238 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1238 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fed25dbbab9 Code: 00 00 00 44 8b 54 24 58 48 89 44 24 30 48 8d 44 24 40 48 89 44 24 38 64 8b 04 25 18 00 00 00 85 c0 75 21 b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6f 48 8b 15 40 a3 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffe1aa1d310 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffe1aa1f478 RCX: 00007fed25dbbab9 RDX: 0000000000080000 RSI: 00007fed261bddd8 RDI: 000000000000000b RBP: 000055f95f73b950 R08: 000055f95f728290 R09: 00007fed25e96b20 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000b R13: 00007fed261bddd8 R14: 0000000000080000 R15: 0000000000000000 Allocated by task 3550: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] net_alloc net/core/net_namespace.c:405 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3101 __do_sys_unshare kernel/fork.c:3175 [inline] __se_sys_unshare kernel/fork.c:3173 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3173 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888078900000 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff888078900000, ffff888078901940) The buggy address belongs to the page: page:ffffea0001e24000 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888078903480 pfn:0x78900 head:ffffea0001e24000 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88805f98e281 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001e4b200 0000000200000002 ffff888011de33c0 raw: ffff888078903480 0000000080040002 00000001ffffffff ffff88805f98e281 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 3550, ts 99342814639, free_ts 99145570259 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] net_alloc net/core/net_namespace.c:405 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3101 __do_sys_unshare kernel/fork.c:3175 [inline] __se_sys_unshare kernel/fork.c:3173 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3173 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_slab mm/slub.c:2015 [inline] discard_slab mm/slub.c:2021 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587 do_slab_free mm/slub.c:3487 [inline] ___cache_free+0xe3/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 getname_flags+0xb8/0x4e0 fs/namei.c:138 do_sys_openat2+0xd2/0x500 fs/open.c:1205 do_sys_open fs/open.c:1227 [inline] __do_sys_openat fs/open.c:1243 [inline] __se_sys_openat fs/open.c:1238 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1238 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff888078900100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078900180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888078900200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078900280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078900300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 00 80 3b 00 0f 85 add %al,-0x7af0ffc5(%rax) 6: 85 02 test %eax,(%rdx) 8: 00 00 add %al,(%rax) a: 80 3d 84 d3 97 0c 00 cmpb $0x0,0xc97d384(%rip) # 0xc97d395 11: 0f 85 78 02 00 00 jne 0x28f 17: c6 05 77 d3 97 0c 01 movb $0x1,0xc97d377(%rip) # 0xc97d395 1e: 48 c7 c7 c0 7d 88 8a mov $0xffffffff8a887dc0,%rdi 25: e9 0e fa ff ff jmp 0xfffffa38 * 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2f: e8 09 bb 1e 00 call 0x1ebb3d 34: 65 8b 0d aa f3 c9 7e mov %gs:0x7ec9f3aa(%rip),%ecx # 0x7ec9f3e5 3b: b0 01 mov $0x1,%al 3d: 85 c9 test %ecx,%ecx 3f: 0f .byte 0xf