================================================================== BUG: KASAN: slab-out-of-bounds in pipe_write+0xe30/0x1000 fs/pipe.c:488 Write of size 8 at addr ffff8880a06c1fa8 by task syz-executor.0/31727 CPU: 1 PID: 31727 Comm: syz-executor.0 Not tainted 5.4.0-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+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:638 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:140 pipe_write+0xe30/0x1000 fs/pipe.c:488 call_write_iter include/linux/fs.h:1902 [inline] new_sync_write+0x4d3/0x770 fs/read_write.c:483 __vfs_write+0xe1/0x110 fs/read_write.c:496 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x220/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a679 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f4ea812ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000041395527 RSI: 0000000020000340 RDI: 0000000000000004 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4ea812b6d4 R13: 00000000004c7969 R14: 00000000004e48d0 R15: 00000000ffffffff Allocated by task 31714: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:485 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:526 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x163/0x770 mm/slab.c:3665 kmalloc_array include/linux/slab.h:598 [inline] kcalloc include/linux/slab.h:609 [inline] pipe_set_size fs/pipe.c:1143 [inline] pipe_fcntl+0x3f7/0x8e0 fs/pipe.c:1209 do_fcntl+0x255/0x1030 fs/fcntl.c:417 __do_sys_fcntl fs/fcntl.c:463 [inline] __se_sys_fcntl fs/fcntl.c:448 [inline] __x64_sys_fcntl+0x16d/0x1e0 fs/fcntl.c:448 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 31263: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] kasan_set_free_info mm/kasan/common.c:334 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:473 kasan_slab_free+0xe/0x10 mm/kasan/common.c:482 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 __free_fdtable+0x62/0x80 fs/file.c:33 put_files_struct fs/file.c:420 [inline] put_files_struct+0x253/0x2f0 fs/file.c:413 exit_files+0x83/0xb0 fs/file.c:445 do_exit+0x8b5/0x2ef0 kernel/exit.c:792 do_group_exit+0x135/0x360 kernel/exit.c:895 __do_sys_exit_group kernel/exit.c:906 [inline] __se_sys_exit_group kernel/exit.c:904 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:904 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a06c1f80 which belongs to the cache kmalloc-64(17:syz0) of size 64 The buggy address is located 40 bytes inside of 64-byte region [ffff8880a06c1f80, ffff8880a06c1fc0) The buggy address belongs to the page: page:ffffea000281b040 refcount:1 mapcount:0 mapping:ffff88808ecfa380 index:0xffff8880a06c1c80 raw: 00fffe0000000200 ffff8880a4f3d338 ffffea0001583a08 ffff88808ecfa380 raw: ffff8880a06c1c80 ffff8880a06c1000 000000010000001b 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a06c1e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880a06c1f00: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff8880a06c1f80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a06c2000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a06c2080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================