================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594 Read of size 1 at addr ffff88802677a7e5 by task syz-executor.2/3642 CPU: 1 PID: 3642 Comm: syz-executor.2 Not tainted 5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x6e9 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline] tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:637 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__ext4_get_inode_loc+0x263/0x11a0 fs/ext4/inode.c:4467 Code: 00 00 00 00 fc ff df 80 3c 02 00 0f 85 3b 0d 00 00 48 8b 74 24 10 31 d2 48 89 e8 4c 89 e7 49 f7 76 20 41 89 d7 48 89 54 24 38 <89> 54 24 40 e8 d4 6c 0f 00 48 8b 0c 24 49 89 c0 44 89 f8 99 41 f7 RSP: 0018:ffffc900031ff8b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc900031ffb60 RCX: 0000000000000000 RDX: 0000000000000486 RSI: ffff88814b089000 RDI: ffff888021508000 RBP: 0000000000000486 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888021508000 R13: 0000000000000010 R14: ffff8880212be000 R15: 0000000000000486 ext4_get_inode_loc+0xba/0x160 fs/ext4/inode.c:4600 ext4_reserve_inode_write+0xca/0x270 fs/ext4/inode.c:5760 __ext4_mark_inode_dirty+0x176/0x8d0 fs/ext4/inode.c:5929 __ext4_unlink+0x46a/0x9d0 fs/ext4/namei.c:3244 ext4_unlink+0x5b0/0x9d0 fs/ext4/namei.c:3278 vfs_unlink+0x351/0x920 fs/namei.c:4229 do_unlinkat+0x3cc/0x650 fs/namei.c:4297 __do_sys_unlink fs/namei.c:4345 [inline] __se_sys_unlink fs/namei.c:4343 [inline] __x64_sys_unlink+0xc6/0x110 fs/namei.c:4343 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+0x63/0xcd RIP: 0033:0x7f205da88bb7 Code: 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc369550b8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f205da88bb7 RDX: 00007ffc369550f0 RSI: 00007ffc369550f0 RDI: 00007ffc36955180 RBP: 00007ffc36955180 R08: 0000000000000001 R09: 00007ffc36954f50 R10: 00005555559f9893 R11: 0000000000000206 R12: 00007f205dae22ce R13: 00007ffc36956240 R14: 00005555559f9810 R15: 00007ffc36956280 Allocated by task 3645: 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:437 [inline] __kasan_slab_alloc+0x85/0xb0 mm/kasan/common.c:470 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc mm/slab.c:3294 [inline] __kmem_cache_alloc_lru mm/slab.c:3471 [inline] kmem_cache_alloc+0x214/0x520 mm/slab.c:3491 kmem_cache_zalloc include/linux/slab.h:723 [inline] net_alloc net/core/net_namespace.c:404 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:459 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:227 ksys_unshare+0x445/0x920 kernel/fork.c:3183 __do_sys_unshare kernel/fork.c:3254 [inline] __se_sys_unshare kernel/fork.c:3252 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3252 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+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x625/0x1210 kernel/workqueue.c:1517 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1805 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x625/0x1210 kernel/workqueue.c:1517 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1805 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 The buggy address belongs to the object at ffff88802677a140 which belongs to the cache net_namespace of size 6784 The buggy address is located 1701 bytes inside of 6784-byte region [ffff88802677a140, ffff88802677bbc0) The buggy address belongs to the physical page: page:ffffea000099de80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802677a140 pfn:0x2677a head:ffffea000099de80 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff88801202cf60 ffff88801202cf60 ffff88801201c500 raw: ffff88802677a140 ffff88802677a140 0000000100000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x2420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 3645, tgid 3645 (syz-executor.4), ts 231812665200, free_ts 87981272813 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515 __alloc_pages_node include/linux/gfp.h:243 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2569 cache_alloc_refill+0x27f/0x380 mm/slab.c:2942 ____cache_alloc mm/slab.c:3018 [inline] ____cache_alloc mm/slab.c:3001 [inline] __do_cache_alloc mm/slab.c:3246 [inline] slab_alloc mm/slab.c:3287 [inline] __kmem_cache_alloc_lru mm/slab.c:3471 [inline] kmem_cache_alloc+0x433/0x520 mm/slab.c:3491 kmem_cache_zalloc include/linux/slab.h:723 [inline] net_alloc net/core/net_namespace.c:404 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:459 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:227 ksys_unshare+0x445/0x920 kernel/fork.c:3183 __do_sys_unshare kernel/fork.c:3254 [inline] __se_sys_unshare kernel/fork.c:3252 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3252 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+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 slab_destroy mm/slab.c:1615 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1635 cache_flusharray mm/slab.c:3389 [inline] ___cache_free+0x2a8/0x3d0 mm/slab.c:3452 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x4f/0x1b0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slab.c:3232 [inline] kmem_cache_alloc_node+0x2f1/0x560 mm/slab.c:3583 __alloc_skb+0x210/0x2f0 net/core/skbuff.c:418 alloc_skb_fclone include/linux/skbuff.h:1307 [inline] tcp_stream_alloc_skb+0x38/0x580 net/ipv4/tcp.c:861 tcp_sendmsg_locked+0xc36/0x2f80 net/ipv4/tcp.c:1325 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1483 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 sock_write_iter+0x291/0x3d0 net/socket.c:1108 call_write_iter include/linux/fs.h:2192 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:578 Memory state around the buggy address: ffff88802677a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802677a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802677a780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802677a800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802677a880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 6 bytes skipped: 0: df 80 3c 02 00 0f filds 0xf00023c(%rax) 6: 85 3b test %edi,(%rbx) 8: 0d 00 00 48 8b or $0x8b480000,%eax d: 74 24 je 0x33 f: 10 31 adc %dh,(%rcx) 11: d2 48 89 rorb %cl,-0x77(%rax) 14: e8 4c 89 e7 49 callq 0x49e78965 19: f7 76 20 divl 0x20(%rsi) 1c: 41 89 d7 mov %edx,%r15d 1f: 48 89 54 24 38 mov %rdx,0x38(%rsp) * 24: 89 54 24 40 mov %edx,0x40(%rsp) <-- trapping instruction 28: e8 d4 6c 0f 00 callq 0xf6d01 2d: 48 8b 0c 24 mov (%rsp),%rcx 31: 49 89 c0 mov %rax,%r8 34: 44 89 f8 mov %r15d,%eax 37: 99 cltd 38: 41 rex.B 39: f7 .byte 0xf7