From: syzbot <syzbot+c37a14770d51a085a520@syzkaller.appspotmail.com>
To: b.zolnierkie@samsung.com, daniel.vetter@ffwll.ch,
ghalat@redhat.com, gregkh@linuxfoundation.org, jslaby@suse.com,
linux-kernel@vger.kernel.org, nico@fluxnic.net,
okash.khawaja@gmail.com, oleksandr@redhat.com, sam@ravnborg.org,
syzkaller-bugs@googlegroups.com, textshell@uchuujin.de
Subject: Re: KASAN: slab-out-of-bounds Read in vc_do_resize
Date: Wed, 22 Jan 2020 07:51:08 -0800 [thread overview]
Message-ID: <0000000000002b41f0059cbc7e2b@google.com> (raw)
In-Reply-To: <00000000000044bcb8059a0a577e@google.com>
syzbot has found a reproducer for the following crash on:
HEAD commit: d96d875e Merge tag 'fixes_for_v5.5-rc8' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11554d85e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=83c00afca9cf5153
dashboard link: https://syzkaller.appspot.com/bug?extid=c37a14770d51a085a520
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1659a721e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16aa59c9e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+c37a14770d51a085a520@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:49 [inline]
BUG: KASAN: slab-out-of-bounds in vc_do_resize+0xb5e/0x1af0 drivers/tty/vt/vt.c:1250
Read of size 192 at addr ffff888095d34540 by task syz-executor536/9034
CPU: 1 PID: 9034 Comm: syz-executor536 Not tainted 5.5.0-rc7-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+0x1fb/0x318 lib/dump_stack.c:118
print_address_description+0x74/0x5c0 mm/kasan/report.c:374
__kasan_report+0x149/0x1c0 mm/kasan/report.c:506
kasan_report+0x26/0x50 mm/kasan/common.c:639
check_memory_region_inline mm/kasan/generic.c:182 [inline]
check_memory_region+0x2b6/0x2f0 mm/kasan/generic.c:192
memcpy+0x28/0x60 mm/kasan/common.c:125
scr_memcpyw include/linux/vt_buffer.h:49 [inline]
vc_do_resize+0xb5e/0x1af0 drivers/tty/vt/vt.c:1250
vc_resize+0x4f/0x60 drivers/tty/vt/vt.c:1304
fbcon_modechanged+0x701/0xdf0 drivers/video/fbdev/core/fbcon.c:2980
fbcon_update_vcs+0x31/0x40 drivers/video/fbdev/core/fbcon.c:3038
fb_set_var+0x8f5/0xdc0 drivers/video/fbdev/core/fbmem.c:1051
do_fb_ioctl+0x55e/0x780 drivers/video/fbdev/core/fbmem.c:1104
fb_ioctl+0xb9/0xf0 drivers/video/fbdev/core/fbmem.c:1180
do_vfs_ioctl+0x6e2/0x19b0 fs/ioctl.c:47
ksys_ioctl fs/ioctl.c:749 [inline]
__do_sys_ioctl fs/ioctl.c:756 [inline]
__se_sys_ioctl fs/ioctl.c:754 [inline]
__x64_sys_ioctl+0xe3/0x120 fs/ioctl.c:754
do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446d49
Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc010171db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000006dbc48 RCX: 0000000000446d49
RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004
RBP: 00000000006dbc40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc4c
R13: 00007ffc8ab7313f R14: 00007fc0101729c0 R15: 0000000000000001
Allocated by task 9034:
save_stack mm/kasan/common.c:72 [inline]
set_track mm/kasan/common.c:80 [inline]
__kasan_kmalloc+0x118/0x1c0 mm/kasan/common.c:513
kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527
__do_kmalloc mm/slab.c:3656 [inline]
__kmalloc+0x254/0x340 mm/slab.c:3665
kmalloc include/linux/slab.h:561 [inline]
kzalloc+0x21/0x40 include/linux/slab.h:670
vc_do_resize+0x2af/0x1af0 drivers/tty/vt/vt.c:1187
vc_resize+0x4f/0x60 drivers/tty/vt/vt.c:1304
fbcon_modechanged+0x701/0xdf0 drivers/video/fbdev/core/fbcon.c:2980
fbcon_update_vcs+0x31/0x40 drivers/video/fbdev/core/fbcon.c:3038
fb_set_var+0x8f5/0xdc0 drivers/video/fbdev/core/fbmem.c:1051
fbcon_resize+0x819/0x11f0 drivers/video/fbdev/core/fbcon.c:2222
resize_screen drivers/tty/vt/vt.c:1126 [inline]
vc_do_resize+0x478/0x1af0 drivers/tty/vt/vt.c:1205
vc_resize+0x4f/0x60 drivers/tty/vt/vt.c:1304
fbcon_modechanged+0x701/0xdf0 drivers/video/fbdev/core/fbcon.c:2980
fbcon_update_vcs+0x31/0x40 drivers/video/fbdev/core/fbcon.c:3038
fb_set_var+0x8f5/0xdc0 drivers/video/fbdev/core/fbmem.c:1051
do_fb_ioctl+0x55e/0x780 drivers/video/fbdev/core/fbmem.c:1104
fb_ioctl+0xb9/0xf0 drivers/video/fbdev/core/fbmem.c:1180
do_vfs_ioctl+0x6e2/0x19b0 fs/ioctl.c:47
ksys_ioctl fs/ioctl.c:749 [inline]
__do_sys_ioctl fs/ioctl.c:756 [inline]
__se_sys_ioctl fs/ioctl.c:754 [inline]
__x64_sys_ioctl+0xe3/0x120 fs/ioctl.c:754
do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 8579:
save_stack mm/kasan/common.c:72 [inline]
set_track mm/kasan/common.c:80 [inline]
kasan_set_free_info mm/kasan/common.c:335 [inline]
__kasan_slab_free+0x12e/0x1e0 mm/kasan/common.c:474
kasan_slab_free+0xe/0x10 mm/kasan/common.c:483
__cache_free mm/slab.c:3426 [inline]
kfree+0x10d/0x220 mm/slab.c:3757
load_elf_binary+0x2c82/0x36d0 fs/binfmt_elf.c:1085
search_binary_handler+0x190/0x5e0 fs/exec.c:1658
exec_binprm fs/exec.c:1701 [inline]
__do_execve_file+0x1565/0x1cc0 fs/exec.c:1821
do_execveat_common fs/exec.c:1867 [inline]
do_execve fs/exec.c:1884 [inline]
__do_sys_execve fs/exec.c:1960 [inline]
__se_sys_execve fs/exec.c:1955 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:1955
do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff888095d34400
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 320 bytes inside of
512-byte region [ffff888095d34400, ffff888095d34600)
The buggy address belongs to the page:
page:ffffea0002574d00 refcount:1 mapcount:0 mapping:ffff8880aa800a80 index:0x0
raw: 00fffe0000000200 ffffea0002741f88 ffffea0002846a48 ffff8880aa800a80
raw: 0000000000000000 ffff888095d34000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888095d34480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888095d34500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888095d34580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888095d34600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888095d34680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
next prev parent reply other threads:[~2020-01-22 15:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-19 8:28 KASAN: slab-out-of-bounds Read in vc_do_resize syzbot
2020-01-22 2:46 ` syzbot
2020-01-22 15:51 ` syzbot [this message]
2020-01-26 11:26 ` syzbot
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