================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff888016ce8258 by task kworker/0:13/4695 CPU: 0 PID: 4695 Comm: kworker/0:13 Not tainted 5.15.118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: rcu_gp process_srcu 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+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 tcp_write_timer_handler+0x1f7/0x9c0 net/ipv4/tcp_timer.c:626 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:646 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:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 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:preempt_count_sub+0x27/0x160 kernel/sched/core.c:5513 Code: 00 00 00 41 56 53 89 fb 48 c7 c0 00 30 3c 91 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 0f b6 04 30 84 c0 0f 85 c0 00 00 00 <83> 3d 12 0c e5 0f 00 75 22 65 8b 05 d1 4b ab 7e 89 c1 81 e1 ff ff RSP: 0018:ffffc90002cefac8 EFLAGS: 00000297 RAX: 0000000000000004 RBX: 0000000000000001 RCX: ffffffff913c3003 RDX: 00000000000002e0 RSI: ffffffff8ad860e0 RDI: 0000000000000001 RBP: 0000000000001c60 R08: ffffffff8428b394 R09: fffff5200059df2d R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000030ef9 R13: 1ffffffff1bc78ff R14: dffffc0000000000 R15: 0000000000000000 delay_tsc+0x4b/0xd0 arch/x86/lib/delay.c:77 try_check_zero+0x2f2/0x360 kernel/rcu/srcutree.c:702 srcu_advance_state kernel/rcu/srcutree.c:1227 [inline] process_srcu+0x1aa/0xc20 kernel/rcu/srcutree.c:1325 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 3535: 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:3094 __do_sys_unshare kernel/fork.c:3168 [inline] __se_sys_unshare kernel/fork.c:3166 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166 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 ffff888016ce8000 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff888016ce8000, ffff888016ce9940) The buggy address belongs to the page: page:ffffea00005b3a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888016ce8000 pfn:0x16ce8 head:ffffea00005b3a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888011dc63c0 raw: ffff888016ce8000 0000000080040003 00000001ffffffff 0000000000000000 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 3535, ts 138203385724, free_ts 138190646759 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:3094 __do_sys_unshare kernel/fork.c:3168 [inline] __se_sys_unshare kernel/fork.c:3166 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166 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] __kmalloc+0x120/0x300 mm/slub.c:4403 kmalloc include/linux/slab.h:596 [inline] tomoyo_realpath_from_path+0xd8/0x5e0 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x273/0x6b0 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x120 security/security.c:1348 vfs_getattr+0x26/0x360 fs/stat.c:157 vfs_statx+0x18f/0x3b0 fs/stat.c:225 vfs_fstatat fs/stat.c:243 [inline] __do_sys_newfstatat fs/stat.c:411 [inline] __se_sys_newfstatat fs/stat.c:405 [inline] __x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405 Memory state around the buggy address: ffff888016ce8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888016ce8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888016ce8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888016ce8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888016ce8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 41 56 add %al,0x56(%rcx) 5: 53 push %rbx 6: 89 fb mov %edi,%ebx 8: 48 c7 c0 00 30 3c 91 mov $0xffffffff913c3000,%rax f: 48 c1 e8 03 shr $0x3,%rax 13: 49 be 00 00 00 00 00 movabs $0xdffffc0000000000,%r14 1a: fc ff df 1d: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax 22: 84 c0 test %al,%al 24: 0f 85 c0 00 00 00 jne 0xea * 2a: 83 3d 12 0c e5 0f 00 cmpl $0x0,0xfe50c12(%rip) # 0xfe50c43 <-- trapping instruction 31: 75 22 jne 0x55 33: 65 8b 05 d1 4b ab 7e mov %gs:0x7eab4bd1(%rip),%eax # 0x7eab4c0b 3a: 89 c1 mov %eax,%ecx 3c: 81 .byte 0x81 3d: e1 ff loope 0x3e 3f: ff .byte 0xff