bisecting fixing commit since 811218eceeaa7618652e1b8d11caeff67ab42072 building syzkaller on a5f86b15f4f60350198e4b98fb7451d45d38a186 testing commit 811218eceeaa7618652e1b8d11caeff67ab42072 with gcc (GCC) 8.4.1 20210217 kernel signature: 4425085d9f9a73ebe58280a41a05f8c99c336cb451fb458d71465b378c699b26 run #0: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #1: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #2: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #3: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #4: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #5: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #6: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #7: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #8: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #9: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #10: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #11: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #12: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #13: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #14: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #15: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #16: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #17: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #18: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #19: crashed: KASAN: use-after-free Write in ext4_write_inline_data testing current HEAD 1722257b8ececec9b3b83a8b14058f8209d78071 testing commit 1722257b8ececec9b3b83a8b14058f8209d78071 with gcc (GCC) 8.4.1 20210217 kernel signature: 02e47695b7a2deebaef61a0229778ea7650220e17cebfcfa8f1a1afb03ce7a34 run #0: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #1: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #2: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #3: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #4: crashed: KASAN: slab-out-of-bounds Write in ext4_write_inline_data run #5: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #6: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #7: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #8: crashed: KASAN: use-after-free Write in ext4_write_inline_data run #9: crashed: KASAN: use-after-free Write in ext4_write_inline_data revisions tested: 2, total time: 22m51.501048126s (build: 15m51.71884521s, test: 6m31.097419115s) the crash still happens on HEAD commit msg: Linux 4.19.193 crash: KASAN: use-after-free Write in ext4_write_inline_data batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 ================================================================== batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! BUG: KASAN: use-after-free in memcpy include/linux/string.h:377 [inline] BUG: KASAN: use-after-free in ext4_write_inline_data.isra.4+0x27a/0x480 fs/ext4/inline.c:245 Write of size 70 at addr ffff8880987c64ef by task syz-executor.4/9793 CPU: 0 PID: 9793 Comm: syz-executor.4 Not tainted 4.19.193-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+0x17c/0x226 lib/dump_stack.c:118 print_address_description.cold.6+0x9/0x211 mm/kasan/report.c:256 IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:396 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13c/0x1b0 mm/kasan/kasan.c:267 memcpy+0x37/0x50 mm/kasan/kasan.c:303 memcpy include/linux/string.h:377 [inline] ext4_write_inline_data.isra.4+0x27a/0x480 fs/ext4/inline.c:245 ext4_write_inline_data_end+0x1df/0x530 fs/ext4/inline.c:754 ext4_write_end+0x167/0xb10 fs/ext4/inode.c:1423 ext4_da_write_end+0x622/0x9b0 fs/ext4/inode.c:3170 generic_perform_write+0x2e3/0x480 mm/filemap.c:3181 __generic_file_write_iter+0x205/0x590 mm/filemap.c:3295 ext4_file_write_iter+0x281/0xe50 fs/ext4/file.c:272 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x443/0x890 fs/read_write.c:487 batman_adv: batadv0: Interface activated: batadv_slave_1 vfs_write+0x150/0x4d0 fs/read_write.c:549 ksys_write+0x103/0x260 fs/read_write.c:599 IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 __do_sys_write fs/read_write.c:611 [inline] __se_sys_write fs/read_write.c:608 [inline] __x64_sys_write+0x6e/0xb0 fs/read_write.c:608 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50 RSP: 002b:00007fcc57701188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 ieee80211 phy7: Selected rate control algorithm 'minstrel_ht' RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready RDX: 0000000000000082 RSI: 0000000020000180 RDI: 0000000000000003 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffd559f161f R14: 00007fcc57701300 R15: 0000000000022000 The buggy address belongs to the page: page:ffffea000261f180 count:0 mapcount:-128 mapping:0000000000000000 index:0xffff8880987c6080 flags: 0xfff00000000000() raw: 00fff00000000000 ffffea0002d48a08 ffffea000261c388 0000000000000000 raw: ffff8880987c6080 0000000000000001 00000000ffffff7f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880987c6380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880987c6400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8880987c6480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880987c6500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880987c6580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================