syzbot


KASAN: user-memory-access Read in do_con_trol

Status: auto-closed as invalid on 2020/07/31 00:46
Reported-by: syzbot+c23287497985af069595@syzkaller.appspotmail.com
First crash: 961d, last: 918d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 KASAN: user-memory-access Read in do_con_trol 1 960d 960d 0/1 auto-closed as invalid on 2020/06/19 12:31
upstream KASAN: user-memory-access Read in do_con_trol 3 883d 882d 0/24 closed as dup on 2020/07/20 22:48

Sample crash report:
EXT4-fs (loop0): VFS: Can't find ext4 filesystem
==================================================================
BUG: KASAN: user-memory-access in memcpy include/linux/string.h:348 [inline]
BUG: KASAN: user-memory-access in scr_memcpyw include/linux/vt_buffer.h:49 [inline]
BUG: KASAN: user-memory-access in delete_char drivers/tty/vt/vt.c:852 [inline]
BUG: KASAN: user-memory-access in csi_P drivers/tty/vt/vt.c:1997 [inline]
BUG: KASAN: user-memory-access in do_con_trol+0x364/0x5c00 drivers/tty/vt/vt.c:2371
Read of size 10 at addr 0000000100000006 by task syz-executor.0/7279

CPU: 0 PID: 7279 Comm: syz-executor.0 Not tainted 4.19.113-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+0x188/0x20d lib/dump_stack.c:118
 kasan_report_error mm/kasan/report.c:352 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x194/0x2b9 mm/kasan/report.c:396
 memcpy+0x20/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:348 [inline]
 scr_memcpyw include/linux/vt_buffer.h:49 [inline]
 delete_char drivers/tty/vt/vt.c:852 [inline]
 csi_P drivers/tty/vt/vt.c:1997 [inline]
 do_con_trol+0x364/0x5c00 drivers/tty/vt/vt.c:2371
 do_con_write.part.0+0xf55/0x1db0 drivers/tty/vt/vt.c:2784
 do_con_write drivers/tty/vt/vt.c:2552 [inline]
 con_write+0x41/0xe0 drivers/tty/vt/vt.c:3119
 process_output_block drivers/tty/n_tty.c:593 [inline]
 n_tty_write+0x3ee/0x1080 drivers/tty/n_tty.c:2331
 do_tty_write drivers/tty/tty_io.c:960 [inline]
 tty_write+0x452/0x790 drivers/tty/tty_io.c:1044
 __vfs_write+0xf7/0x760 fs/read_write.c:485
 vfs_write+0x206/0x550 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c849
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f94deff7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f94deff86d4 RCX: 000000000045c849
RDX: 0000000000000078 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000cdc R14: 00000000004cf002 R15: 000000000076bf0c
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-19 2020/04/02 00:45 linux-4.19.y 54b4fa6d3955 a34e2c33 .config log report
ci2-linux-4-19 2020/02/19 14:04 linux-4.19.y 9b15f7fae677 47fae6e9 .config log report
* Struck through repros no longer work on HEAD.