================================================================== BUG: KASAN: slab-out-of-bounds in cap_convert_nscap+0x501/0x610 security/commoncap.c:498 handle_userfault: 139 callbacks suppressed FAULT_FLAG_ALLOW_RETRY missing 30 CPU: 1 PID: 12314 Comm: syz-executor2 Not tainted 4.15.0-rc5+ #243 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 handle_userfault+0x12fa/0x24c0 fs/userfaultfd.c:427 do_anonymous_page mm/memory.c:3121 [inline] handle_pte_fault mm/memory.c:3935 [inline] __handle_mm_fault+0x32a3/0x3ce0 mm/memory.c:4061 handle_mm_fault+0x334/0x8d0 mm/memory.c:4098 __do_page_fault+0x5c9/0xc90 arch/x86/mm/fault.c:1429 do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1504 page_fault+0x2c/0x60 arch/x86/entry/entry_64.S:1243 RIP: 0010:fault_in_pages_readable include/linux/pagemap.h:601 [inline] RIP: 0010:iov_iter_fault_in_readable+0x1a7/0x410 lib/iov_iter.c:421 RSP: 0018:ffff8801c3a67928 EFLAGS: 00010246 RAX: 0000000000010000 RBX: 0000000020011fd2 RCX: ffffffff8256d2e1 RDX: 000000000000010b RSI: ffffc90001ca6000 RDI: ffff8801c3a67d28 RBP: ffff8801c3a67a08 R08: ffff8801d7a0bc00 R09: 1ffff1003874cee7 R10: ffff8801c3a67858 R11: 0000000000000003 R12: 1ffff1003874cf28 R13: ffff8801c3a679e0 R14: 0000000000000000 R15: ffff8801c3a67d20 generic_perform_write+0x200/0x600 mm/filemap.c:3129 __generic_file_write_iter+0x366/0x5b0 mm/filemap.c:3264 generic_file_write_iter+0x399/0x790 mm/filemap.c:3292 call_write_iter include/linux/fs.h:1772 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452ac9 RSP: 002b:00007f3dd19bec58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f3dd19bf700 RCX: 0000000000452ac9 RDX: 0000000000000030 RSI: 0000000020011fd2 RDI: 0000000000000015 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 R13: 0000000000a2f7ef R14: 00007f3dd19bf9c0 R15: 0000000000000000 Read of size 4 at addr ffff8801d8010800 by task syz-executor5/12339 CPU: 0 PID: 12339 Comm: syz-executor5 Not tainted 4.15.0-rc5+ #243 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 cap_convert_nscap+0x501/0x610 security/commoncap.c:498 setxattr+0x365/0x400 fs/xattr.c:446 SYSC_fsetxattr fs/xattr.c:508 [inline] SyS_fsetxattr+0x130/0x190 fs/xattr.c:497 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452ac9 RSP: 002b:00007f7f44318c58 EFLAGS: 00000212 ORIG_RAX: 00000000000000be RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9 RDX: 0000000020f09000 RSI: 000000002039ffec RDI: 0000000000000014 RBP: 0000000000000567 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000212 R12: 00000000006f6248 R13: 00000000ffffffff R14: 00007f7f443196d4 R15: 0000000000000000 Allocated by task 12339: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 __do_kmalloc_node mm/slab.c:3672 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3679 kmalloc_node include/linux/slab.h:541 [inline] kvmalloc_node+0x99/0xd0 mm/util.c:397 kvmalloc include/linux/mm.h:541 [inline] setxattr+0x152/0x400 fs/xattr.c:435 SYSC_fsetxattr fs/xattr.c:508 [inline] SyS_fsetxattr+0x130/0x190 fs/xattr.c:497 entry_SYSCALL_64_fastpath+0x1f/0x96 Freed by task 9112: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3488 [inline] kfree+0xd6/0x260 mm/slab.c:3803 kvm_io_bus_register_dev+0x33c/0x5e0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3596 kvm_pic_init+0x229/0x360 arch/x86/kvm/i8259.c:608 kvm_arch_vm_ioctl+0x35f/0x1e60 arch/x86/kvm/x86.c:4085 kvm_vm_ioctl+0x227/0x1c60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3122 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 entry_SYSCALL_64_fastpath+0x1f/0x96 The buggy address belongs to the object at ffff8801d8010800 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8801d8010800, ffff8801d8010820) The buggy address belongs to the page: page:0000000055570624 count:1 mapcount:0 mapping:00000000a91e90e7 index:0xffff8801d8010fc1 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d8010000 ffff8801d8010fc1 0000000100000036 raw: ffffea00070b25a0 ffffea0007600560 ffff8801dac001c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d8010700: 00 02 fc fc fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d8010780: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc >ffff8801d8010800: 01 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff8801d8010880: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d8010900: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ==================================================================