================================================================== BUG: KASAN: slab-out-of-bounds in tcp_retransmit_timer+0x2d4c/0x3240 net/ipv4/tcp_timer.c:500 Read of size 8 at addr ffff8880a7d50350 by task syz-fuzzer/6852 CPU: 0 PID: 6852 Comm: syz-fuzzer 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: 0033:0x41f929 Code: eb 07 49 8d 7b 08 48 89 f9 48 39 d1 0f 83 62 01 00 00 48 89 4c 24 50 48 85 c9 74 0b 83 fe 03 0f 83 f9 00 00 00 ff c6 0f b6 3b <49> 89 cb 89 f1 41 89 fc d3 ef 49 83 fb 08 74 0a 0f ba e7 04 0f 83 RSP: 002b:000000c000049ea8 EFLAGS: 00000246 RAX: 0000000000203002 RBX: 00007fbf3dfe88c8 RCX: 0000000000000000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 00000000000000df RBP: 000000c000049f28 R08: 00007fbf3e1a6fff R09: 000000c008831900 R10: 000000c00002fe98 R11: 000000000000001b R12: 0000000000000011 R13: 000000c000000f00 R14: 000000c00af24180 R15: 0000000000000000 Allocated by task 3904: 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] vfs_statx+0x14e/0x390 fs/stat.c:202 vfs_lstat include/linux/fs.h:3175 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:374 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 3904: 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] vfs_statx+0x14e/0x390 fs/stat.c:202 vfs_lstat include/linux/fs.h:3175 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:374 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 ffff8880a7d503c0 which belongs to the cache names_cache of size 4096 The buggy address is located 112 bytes to the left of 4096-byte region [ffff8880a7d503c0, ffff8880a7d513c0) The buggy address belongs to the page: page:00000000b82b4191 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa7d50 head:00000000b82b4191 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea000196af08 ffffea00025af588 ffff88821bc47a00 raw: 0000000000000000 ffff8880a7d503c0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a7d50200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a7d50280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a7d50300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a7d50380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff8880a7d50400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================