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BUG: KASAN: slab-out-of-bounds in tcp_retransmit_timer+0x2a56/0x2e70 net/ipv4/tcp_timer.c:500
Read of size 8 at addr ffff88806e4d44d0 by task syz-executor.4/12891

CPU: 1 PID: 12891 Comm: syz-executor.4 Not tainted 5.6.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374
 __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:506
 kasan_report+0xe/0x20 mm/kasan/common.c:641
 tcp_retransmit_timer+0x2a56/0x2e70 net/ipv4/tcp_timer.c:500
 tcp_write_timer_handler+0x686/0x8a0 net/ipv4/tcp_timer.c:611
 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:631
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1405
 expire_timers kernel/time/timer.c:1450 [inline]
 __run_timers kernel/time/timer.c:1774 [inline]
 __run_timers kernel/time/timer.c:1741 [inline]
 run_timer_softirq+0x623/0x1600 kernel/time/timer.c:1787
 __do_softirq+0x26c/0x9f7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x192/0x1d0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:546 [inline]
 smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1140
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
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 70 8c 94 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d 8e 51 cf 01 00 74 25 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 0b bf 89 f9 65 8b 05 cc e3 3c 78 85 c0 74 02 5d
RSP: 0018:ffffc900019c7940 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff132918e RBX: ffff8880a1c9a440 RCX: 1ffffffff185c76a
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8880a1c9acfc
RBP: ffff8880ae737900 R08: 0000000000000001 R09: fffffbfff1856196
R10: fffffbfff1856195 R11: ffffffff8c2b0caf R12: ffff8880ae737900
R13: ffff888069f36240 R14: 0000000000000000 R15: 0000000000000001
 finish_lock_switch kernel/sched/core.c:3117 [inline]
 finish_task_switch+0x147/0x750 kernel/sched/core.c:3217
 context_switch kernel/sched/core.c:3381 [inline]
 __schedule+0x93f/0x1ff0 kernel/sched/core.c:4094
 preempt_schedule_irq+0xb0/0x150 kernel/sched/core.c:4351
 retint_kernel+0x1b/0x2b
RIP: 0010:dquot_alloc_inode+0x0/0x5b0 fs/quota/dquot.c:1721
Code: e6 f3 d1 ff e9 00 fc ff ff 48 89 c7 48 89 04 24 e8 d5 f3 d1 ff 48 8b 04 24 e9 8f fd ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 <41> 57 41 56 41 55 41 54 55 48 89 fd 53 48 bb 00 00 00 00 00 fc ff
RSP: 0018:ffffc900019c7b50 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffff8880a1c9a440 RBX: 0000000000000000 RCX: ffffffff81fd7419
RDX: 0000000000000000 RSI: ffffffff81fd7426 RDI: ffff88804fe064f8
RBP: ffffc900019c7d20 R08: ffff8880a1c9a440 R09: ffffed1009fc0c63
R10: ffffed1009fc0c62 R11: ffff88804fe06317 R12: ffff88804fe06538
R13: 000000000000a000 R14: ffff88804fe06310 R15: ffff88821496e000
 __ext4_new_inode+0x2e22/0x57e0 fs/ext4/ialloc.c:1143
 ext4_symlink+0x44f/0xe50 fs/ext4/namei.c:3295
 vfs_symlink fs/namei.c:4201 [inline]
 vfs_symlink+0x374/0x580 fs/namei.c:4187
 do_symlinkat+0x215/0x280 fs/namei.c:4228
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45c5b7
Code: 0f 1f 00 b8 5c 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 6d b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 4d b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffed72690d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045c5b7
RDX: 00007ffed7269177 RSI: 00000000004c23bc RDI: 00007ffed7269160
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000017
R10: 0000000000000075 R11: 0000000000000206 R12: 0000000000000001
R13: 00007ffed7269110 R14: 0000000000000000 R15: 00007ffed7269120

Allocated by task 4113:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:515 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc mm/slab.c:3320 [inline]
 kmem_cache_alloc+0x11b/0x740 mm/slab.c:3484
 getname_flags fs/namei.c:138 [inline]
 getname_flags+0xd2/0x5b0 fs/namei.c:128
 user_path_at_empty+0x2a/0x50 fs/namei.c:2746
 user_path_at include/linux/namei.h:58 [inline]
 vfs_statx+0x119/0x1e0 fs/stat.c:197
 vfs_lstat include/linux/fs.h:3279 [inline]
 __do_sys_newlstat+0x96/0x120 fs/stat.c:364
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 4113:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:337 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:476
 __cache_free mm/slab.c:3426 [inline]
 kmem_cache_free+0x7f/0x320 mm/slab.c:3694
 putname+0xe1/0x120 fs/namei.c:259
 filename_lookup+0x282/0x3e0 fs/namei.c:2475
 user_path_at include/linux/namei.h:58 [inline]
 vfs_statx+0x119/0x1e0 fs/stat.c:197
 vfs_lstat include/linux/fs.h:3279 [inline]
 __do_sys_newlstat+0x96/0x120 fs/stat.c:364
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff88806e4d4740
 which belongs to the cache names_cache of size 4096
The buggy address is located 624 bytes to the left of
 4096-byte region [ffff88806e4d4740, ffff88806e4d5740)
The buggy address belongs to the page:
page:ffffea0001b93500 refcount:1 mapcount:0 mapping:ffff8880aa1eb000 index:0x0 compound_mapcount: 0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea0002900f08 ffffea0001425288 ffff8880aa1eb000
raw: 0000000000000000 ffff88806e4d4740 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88806e4d4380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88806e4d4400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88806e4d4480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff88806e4d4500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88806e4d4580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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