bisecting fixing commit since 9f31eb60d7a23536bf3902d4dc602f10c822b79e building syzkaller on 34bf9440bd06034f86b5d9ac8afbf078129cbdae testing commit 9f31eb60d7a23536bf3902d4dc602f10c822b79e with gcc (GCC) 8.1.0 kernel signature: eae9fad0ee205343cf7669f748aacbab861d1a26 run #0: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #1: crashed: KASAN: use-after-free Read in scatterwalk_copychunks run #2: crashed: general protection fault in scatterwalk_copychunks run #3: crashed: general protection fault in scatterwalk_map_and_copy run #4: crashed: KASAN: use-after-free Read in scatterwalk_copychunks run #5: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #6: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #7: crashed: KASAN: use-after-free Read in scatterwalk_copychunks run #8: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #9: crashed: general protection fault in scatterwalk_copychunks testing current HEAD cb1f9a169a0e197f93816ace48a6520e8640809d testing commit cb1f9a169a0e197f93816ace48a6520e8640809d with gcc (GCC) 8.1.0 kernel signature: 26e871cdd5c7ddd82dd4a9b0b65a5d217bd303fa run #0: crashed: KASAN: use-after-free Read in scatterwalk_copychunks run #1: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #2: crashed: KASAN: use-after-free Read in scatterwalk_copychunks run #3: crashed: KASAN: use-after-free Read in scatterwalk_copychunks run #4: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #5: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #6: crashed: general protection fault in scatterwalk_copychunks run #7: crashed: general protection fault in scatterwalk_copychunks run #8: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #9: crashed: KASAN: use-after-free Read in scatterwalk_copychunks revisions tested: 2, total time: 25m9.256356527s (build: 17m45.596832764s, test: 6m32.437010187s) the crash still happens on HEAD commit msg: Linux 4.19.94 crash: KASAN: use-after-free Read in scatterwalk_copychunks RBP: 000000000075bf20 R08: 0000000100000300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd716ee16d4 R13: 00000000004c87fb R14: 00000000004de630 R15: 0000000000000005 ================================================================== IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready BUG: KASAN: use-after-free in memcpy include/linux/string.h:348 [inline] BUG: KASAN: use-after-free in memcpy_dir crypto/scatterwalk.c:28 [inline] BUG: KASAN: use-after-free in scatterwalk_copychunks+0x1e1/0x610 crypto/scatterwalk.c:43 Read of size 4094 at addr ffff8880902ca000 by task syz-executor.4/7103 CPU: 0 PID: 7103 Comm: syz-executor.4 Not tainted 4.19.94-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+0x123/0x177 lib/dump_stack.c:118 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 memcpy+0x23/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:348 [inline] memcpy_dir crypto/scatterwalk.c:28 [inline] scatterwalk_copychunks+0x1e1/0x610 crypto/scatterwalk.c:43 scatterwalk_map_and_copy+0x128/0x190 crypto/scatterwalk.c:72 gcmaes_encrypt.constprop.15+0x6d6/0xda0 arch/x86/crypto/aesni-intel_glue.c:956 generic_gcmaes_encrypt+0xfd/0x150 arch/x86/crypto/aesni-intel_glue.c:1297 crypto_aead_encrypt include/crypto/aead.h:335 [inline] gcmaes_wrapper_encrypt+0x109/0x180 arch/x86/crypto/aesni-intel_glue.c:1130 crypto_aead_encrypt include/crypto/aead.h:335 [inline] tls_do_encryption net/tls/tls_sw.c:193 [inline] tls_push_record+0x966/0x1720 net/tls/tls_sw.c:228 tls_sw_sendpage+0x458/0xc00 net/tls/tls_sw.c:585 inet_sendpage+0x122/0x600 net/ipv4/af_inet.c:815 kernel_sendpage+0x60/0xd0 net/socket.c:3377 sock_sendpage+0x6d/0xd0 net/socket.c:847 pipe_to_sendpage+0x212/0x430 fs/splice.c:452 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x2cb/0x720 fs/splice.c:627 splice_from_pipe+0xbb/0x120 fs/splice.c:662 generic_splice_sendpage+0x10/0x20 fs/splice.c:833 do_splice_from fs/splice.c:852 [inline] do_splice+0x4fd/0x12d0 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1408 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd716ee0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007fd716ee0c90 RCX: 00000000004592c9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000100000300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd716ee16d4 R13: 00000000004c87fb R14: 00000000004de630 R15: 0000000000000005 The buggy address belongs to the page: page:ffffea000240b280 count:0 mapcount:-128 mapping:0000000000000000 index:0xffff8880902cab80 flags: 0x1fffc0000000000() raw: 01fffc0000000000 ffffea00022e9588 ffffea0002544188 0000000000000000 raw: ffff8880902cab80 0000000000000001 00000000ffffff7f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880902c9f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880902c9f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880902ca000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880902ca080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880902ca100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================