================================================================== BUG: KASAN: slab-out-of-bounds in tcp_retransmit_timer+0x2d4c/0x3240 net/ipv4/tcp_timer.c:500 Read of size 8 at addr ffff88805f4c23d0 by task syz-executor.4/15414 CPU: 1 PID: 15414 Comm: syz-executor.4 Not tainted 5.9.0-rc1-syzkaller #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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 tcp_retransmit_timer+0x2d4c/0x3240 net/ipv4/tcp_timer.c:500 tcp_write_timer_handler+0x79b/0xa60 net/ipv4/tcp_timer.c:611 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:631 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755 __run_timers kernel/time/timer.c:1736 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768 __do_softirq+0x2de/0xa24 kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x1f3/0x230 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:unwind_next_frame+0x1bc/0x1f90 arch/x86/kernel/unwind_orc.c:449 Code: ea 83 e2 07 38 d0 7f 08 84 c0 0f 85 39 0a 00 00 4c 89 e1 41 0f b6 47 35 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 <0f> 85 6e 15 00 00 49 8b 4f 48 3c 01 49 c7 c0 60 54 b6 89 48 83 d9 RSP: 0018:ffffc900062b73b0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff92000c56e7e RCX: 1ffff92000c56e9a RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff88805b4df518 RBP: 0000000000000001 R08: ffffffff8b7d819a R09: 0000000000000001 R10: 000000000007201e R11: 0000000000000001 R12: ffffc900062b74d0 R13: ffffc900062b74bd R14: ffffc900062b74d8 R15: ffffc900062b7488 arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0xae/0x550 net/core/skbuff.c:210 alloc_skb_fclone include/linux/skbuff.h:1144 [inline] tipc_buf_acquire+0x28/0xf0 net/tipc/msg.c:76 tipc_msg_build+0xf0/0x10c0 net/tipc/msg.c:396 __tipc_sendstream+0x6d9/0x1210 net/tipc/socket.c:1601 tipc_sendstream+0x4c/0x70 net/tipc/socket.c:1532 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:671 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5b9 Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f61aa410c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000027bc0 RCX: 000000000045d5b9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000005 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007fff732ab31f R14: 00007f61aa4119c0 R15: 000000000118cf4c Allocated by task 15125: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:518 [inline] slab_alloc mm/slab.c:3312 [inline] kmem_cache_alloc+0x138/0x3a0 mm/slab.c:3482 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags fs/namei.c:2646 [inline] user_path_at_empty+0xa1/0x100 fs/namei.c:2646 user_path_at include/linux/namei.h:59 [inline] do_faccessat+0x129/0x820 fs/open.c:423 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 15125: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kmem_cache_free.part.0+0x67/0x1f0 mm/slab.c:3693 putname+0xe1/0x120 fs/namei.c:259 filename_lookup+0x3b1/0x560 fs/namei.c:2376 user_path_at include/linux/namei.h:59 [inline] do_faccessat+0x129/0x820 fs/open.c:423 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88805f4c25c0 which belongs to the cache names_cache of size 4096 The buggy address is located 496 bytes to the left of 4096-byte region [ffff88805f4c25c0, ffff88805f4c35c0) The buggy address belongs to the page: page:00000000167d0583 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5f4c2 head:00000000167d0583 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00016ae788 ffffea00023f9908 ffff88821bc47a00 raw: 0000000000000000 ffff88805f4c25c0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805f4c2280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805f4c2300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805f4c2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805f4c2400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805f4c2480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================