================================================================== BUG: KASAN: slab-out-of-bounds in tcp_retransmit_timer+0x2d4c/0x3240 net/ipv4/tcp_timer.c:500 Read of size 8 at addr ffff8880a11e2410 by task syz-executor.5/21429 CPU: 1 PID: 21429 Comm: syz-executor.5 Not tainted 5.9.0-rc3-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+0x198/0x1fd 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+0xb3/0x1d0 kernel/time/timer.c:1768 __do_softirq+0x1f8/0xb23 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+0x235/0x280 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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199 Code: c0 b8 6b fc 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d c6 df d3 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 ab 59 28 f9 65 8b 05 74 72 d9 77 85 c0 74 02 5d RSP: 0018:ffffc9000602fb50 EFLAGS: 00000286 RAX: 1ffffffff13f8d77 RBX: ffff88808e4ca040 RCX: 1ffffffff16b2529 RDX: dffffc0000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffff8880ae535e00 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ae535e00 R13: ffff8880a3c5c3c0 R14: 0000000000000000 R15: 0000000000000000 finish_lock_switch kernel/sched/core.c:3517 [inline] finish_task_switch+0x150/0x790 kernel/sched/core.c:3617 context_switch kernel/sched/core.c:3781 [inline] __schedule+0xed1/0x2280 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x222/0x650 kernel/time/hrtimer.c:1883 hrtimer_nanosleep+0x1f9/0x430 kernel/time/hrtimer.c:1936 __do_sys_nanosleep kernel/time/hrtimer.c:1970 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1957 [inline] __x64_sys_nanosleep+0x1dc/0x260 kernel/time/hrtimer.c:1957 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c641 Code: 75 14 b8 23 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 64 cd fb ff c3 48 83 ec 08 e8 ea 46 00 00 48 89 04 24 b8 23 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 33 47 00 00 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffc17e3f4a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 00000000000832b2 RCX: 000000000045c641 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffc17e3f4b0 RBP: 0000000000000001 R08: 0000000000e557b5 R09: 0000000000e557b9 R10: 00007ffc17e3f5b0 R11: 0000000000000293 R12: 000000000118cf40 R13: 000000000118d9c0 R14: ffffffffffffffff R15: 000000000118d09c Allocated by task 3920: 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+0x13a/0x3f0 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 do_readlinkat+0xcd/0x2f0 fs/stat.c:419 __do_sys_readlinkat fs/stat.c:446 [inline] __se_sys_readlinkat fs/stat.c:443 [inline] __x64_sys_readlinkat+0x93/0xf0 fs/stat.c:443 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 3920: 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+0x74/0x1e0 mm/slab.c:3693 putname+0xe1/0x120 fs/namei.c:259 filename_lookup+0x3b1/0x560 fs/namei.c:2376 do_readlinkat+0xcd/0x2f0 fs/stat.c:419 __do_sys_readlinkat fs/stat.c:446 [inline] __se_sys_readlinkat fs/stat.c:443 [inline] __x64_sys_readlinkat+0x93/0xf0 fs/stat.c:443 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 ffff8880a11e2b40 which belongs to the cache names_cache of size 4096 The buggy address is located 1840 bytes to the left of 4096-byte region [ffff8880a11e2b40, ffff8880a11e3b40) The buggy address belongs to the page: page:000000001ef4633c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa11e2 head:000000001ef4633c order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0001372588 ffffea000155bd88 ffff88821bc47a00 raw: 0000000000000000 ffff8880a11e2b40 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a11e2300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a11e2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a11e2400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a11e2480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a11e2500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================