bisecting fixing commit since 3f2ecb86cb909da0b9157fd2952ad79924cbe5ae building syzkaller on bca53db974f570410921f59b8c2c59a3d263cb44 testing commit 3f2ecb86cb909da0b9157fd2952ad79924cbe5ae with gcc (GCC) 8.1.0 kernel signature: 45cf54c0ba034077f0e3f75b3c8794308e60087e076d291ae04537fe48c0f6aa run #0: crashed: KASAN: use-after-free Read in squashfs_export_iget run #1: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #2: crashed: KASAN: use-after-free Read in squashfs_export_iget run #3: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #4: crashed: KASAN: use-after-free Read in squashfs_export_iget run #5: crashed: KASAN: use-after-free Read in squashfs_export_iget run #6: crashed: KASAN: use-after-free Read in squashfs_export_iget run #7: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #8: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #9: crashed: KASAN: use-after-free Read in squashfs_export_iget testing current HEAD f79dc86058bc0c8317eea2a0f968382c6ffb0cfb testing commit f79dc86058bc0c8317eea2a0f968382c6ffb0cfb with gcc (GCC) 8.1.0 kernel signature: cd042aa41554fc9f700d17cd5fcb3763f1a2bb7348328fffd658532fed472037 run #0: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #1: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #2: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #3: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #4: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #5: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #6: crashed: KASAN: use-after-free Read in squashfs_export_iget run #7: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget run #8: crashed: KASAN: use-after-free Read in squashfs_export_iget run #9: crashed: KASAN: slab-out-of-bounds Read in squashfs_export_iget revisions tested: 2, total time: 23m19.700192145s (build: 17m7.985301202s, test: 5m33.819952544s) the crash still happens on HEAD commit msg: Linux 4.14.215 crash: KASAN: slab-out-of-bounds Read in squashfs_export_iget IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready ================================================================== BUG: KASAN: slab-out-of-bounds in squashfs_inode_lookup fs/squashfs/export.c:57 [inline] BUG: KASAN: slab-out-of-bounds in squashfs_export_iget+0x220/0x240 fs/squashfs/export.c:82 Read of size 8 at addr ffff88809da06650 by task syz-executor.3/9709 CPU: 1 PID: 9709 Comm: syz-executor.3 Not tainted 4.14.215-syzkaller #0 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+0x14b/0x1f1 lib/dump_stack.c:58 print_address_description.cold.6+0x9/0x1ca mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report.cold.7+0x11a/0x2d4 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 squashfs_inode_lookup fs/squashfs/export.c:57 [inline] squashfs_export_iget+0x220/0x240 fs/squashfs/export.c:82 squashfs_fh_to_dentry+0x49/0x70 fs/squashfs/export.c:97 exportfs_decode_fh+0x10a/0x6df fs/exportfs/expfs.c:433 do_handle_to_path fs/fhandle.c:153 [inline] handle_to_path fs/fhandle.c:208 [inline] do_handle_open+0x25e/0x5c0 fs/fhandle.c:224 SYSC_open_by_handle_at fs/fhandle.c:266 [inline] SyS_open_by_handle_at+0xc/0x10 fs/fhandle.c:257 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e159 RSP: 002b:00007fa10d22fc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000130 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e159 RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000003 RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffe1a70bccf R14: 00007fa10d2309c0 R15: 000000000119bf8c Allocated by task 9547: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:551 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:536 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc+0x12e/0x3e0 mm/slab.c:3552 getname_flags+0xb8/0x510 fs/namei.c:138 getname+0xd/0x10 fs/namei.c:209 do_sys_open+0x13f/0x340 fs/open.c:1075 SYSC_open fs/open.c:1099 [inline] SyS_open+0x19/0x20 fs/open.c:1094 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 9547: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xab/0x190 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kmem_cache_free+0x80/0x2d0 mm/slab.c:3758 putname+0xa8/0xe0 fs/namei.c:259 do_sys_open+0x161/0x340 fs/open.c:1090 SYSC_open fs/open.c:1099 [inline] SyS_open+0x19/0x20 fs/open.c:1094 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff88809da06d40 which belongs to the cache names_cache of size 4096 The buggy address is located 1776 bytes to the left of 4096-byte region [ffff88809da06d40, ffff88809da07d40) The buggy address belongs to the page: page:ffffea0002768180 count:1 mapcount:0 mapping:ffff88809da06d40 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffff88809da06d40 0000000000000000 0000000100000001 raw: ffffea0002768120 ffffea00025fa620 ffff88823f830dc0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809da06500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809da06580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88809da06600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88809da06680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809da06700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready