bisecting fixing commit since cbfa1702aaf69b2311ea1b35e04f113c48368c67 building syzkaller on 5ef9c29141f85f210b326ce68718498ae0c1fd35 testing commit cbfa1702aaf69b2311ea1b35e04f113c48368c67 with gcc (GCC) 8.1.0 kernel signature: f4a6e78de65ad3bb090f566fed111e4935b2fae4c21059a52205338f5d81a1bc all runs: crashed: KASAN: slab-out-of-bounds Read in build_segment_manager testing current HEAD c196b3a9c83ae3491280b739d231d02b3cb9d041 testing commit c196b3a9c83ae3491280b739d231d02b3cb9d041 with gcc (GCC) 8.1.0 kernel signature: 6366eb42f5e181483d2530b5ce38966f0b5b2a11c944f5be5de86700b8462504 all runs: crashed: KASAN: slab-out-of-bounds Read in build_segment_manager revisions tested: 2, total time: 24m50.936712977s (build: 18m15.646932206s, test: 6m4.825053768s) the crash still happens on HEAD commit msg: Linux 4.14.210 crash: KASAN: slab-out-of-bounds Read in build_segment_manager IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready F2FS-fs (loop2): invalid crc value IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready ================================================================== IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready BUG: KASAN: slab-out-of-bounds in init_min_max_mtime fs/f2fs/segment.c:3497 [inline] BUG: KASAN: slab-out-of-bounds in build_segment_manager+0x7ca1/0x8660 fs/f2fs/segment.c:3577 Read of size 8 at addr ffff8881f41c30a8 by task syz-executor.2/7254 CPU: 1 PID: 7254 Comm: syz-executor.2 Not tainted 4.14.210-syzkaller #0 device veth0_macvtap entered promiscuous mode 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 IPv6: ADDRCONF(NETDEV_UP): macvtap0: link is not ready init_min_max_mtime fs/f2fs/segment.c:3497 [inline] build_segment_manager+0x7ca1/0x8660 fs/f2fs/segment.c:3577 f2fs_fill_super+0x282d/0x5d40 fs/f2fs/super.c:2581 mount_bdev+0x26f/0x330 fs/super.c:1134 f2fs_mount+0x10/0x20 fs/f2fs/super.c:2776 mount_fs+0x7f/0x269 fs/super.c:1237 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x352/0x2af0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3072 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4608da RSP: 002b:00007fcd55c6fa88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fcd55c6fb20 RCX: 00000000004608da RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fcd55c6fae0 RBP: 00007fcd55c6fae0 R08: 00007fcd55c6fb20 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000 R13: 0000000020000100 R14: 0000000020000140 R15: 0000000020000200 Allocated by task 7254: 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 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node+0x50/0x70 mm/slab.c:3689 kmalloc_node include/linux/slab.h:530 [inline] kvmalloc_node+0x70/0x80 mm/util.c:397 kvmalloc include/linux/mm.h:531 [inline] kvzalloc include/linux/mm.h:539 [inline] build_sit_info fs/f2fs/segment.c:3108 [inline] build_segment_manager+0x9f8/0x8660 fs/f2fs/segment.c:3553 f2fs_fill_super+0x282d/0x5d40 fs/f2fs/super.c:2581 mount_bdev+0x26f/0x330 fs/super.c:1134 f2fs_mount+0x10/0x20 fs/f2fs/super.c:2776 mount_fs+0x7f/0x269 fs/super.c:1237 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x352/0x2af0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xb1/0xd0 fs/namespace.c:3072 device veth1_macvtap entered promiscuous mode do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8881f41c2c00 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1192 bytes inside of 2048-byte region [ffff8881f41c2c00, ffff8881f41c3400) The buggy address belongs to the page: page:ffffea0007d07080 count:1 mapcount:0 mapping:ffff8881f41c2380 index:0x0 compound_mapcount: 0 flags: 0x17ffe0000008100(slab|head) raw: 017ffe0000008100 ffff8881f41c2380 0000000000000000 0000000100000003 raw: ffffea0007d3e220 ffffea0007d03520 ffff8881f6000c40 0000000000000000 IPv6: ADDRCONF(NETDEV_UP): macsec0: link is not ready page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881f41c2f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881f41c3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881f41c3080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8881f41c3100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready ffff8881f41c3180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================