From: George Kennedy <george.kennedy@xxxxxxxxxx>
[ Upstream commit 1b42b1a36fc946f0d7088425b90d491b4257ca3e ]
Ensure that the VID header offset + VID header size does not exceed
the allocated area to avoid slab OOB.
BUG: KASAN: slab-out-of-bounds in crc32_body lib/crc32.c:111 [inline]
BUG: KASAN: slab-out-of-bounds in crc32_le_generic lib/crc32.c:179 [inline]
BUG: KASAN: slab-out-of-bounds in crc32_le_base+0x58c/0x626 lib/crc32.c:197
Read of size 4 at addr ffff88802bb36f00 by task syz-executor136/1555
CPU: 2 PID: 1555 Comm: syz-executor136 Tainted: G W
6.0.0-1868 #1
Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7860+a7792d29
04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x85/0xad lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold.13+0xb6/0x6bb mm/kasan/report.c:433
kasan_report+0xa7/0x11b mm/kasan/report.c:495
crc32_body lib/crc32.c:111 [inline]
crc32_le_generic lib/crc32.c:179 [inline]
crc32_le_base+0x58c/0x626 lib/crc32.c:197
ubi_io_write_vid_hdr+0x1b7/0x472 drivers/mtd/ubi/io.c:1067
create_vtbl+0x4d5/0x9c4 drivers/mtd/ubi/vtbl.c:317
create_empty_lvol drivers/mtd/ubi/vtbl.c:500 [inline]
ubi_read_volume_table+0x67b/0x288a drivers/mtd/ubi/vtbl.c:812
ubi_attach+0xf34/0x1603 drivers/mtd/ubi/attach.c:1601
ubi_attach_mtd_dev+0x6f3/0x185e drivers/mtd/ubi/build.c:965
ctrl_cdev_ioctl+0x2db/0x347 drivers/mtd/ubi/cdev.c:1043
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x213 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3e/0x86 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0x0
RIP: 0033:0x7f96d5cf753d
Code:
RSP: 002b:00007fffd72206f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f96d5cf753d
RDX: 0000000020000080 RSI: 0000000040186f40 RDI: 0000000000000003
RBP: 0000000000400cd0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400be0
R13: 00007fffd72207e0 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Allocated by task 1555:
kasan_save_stack+0x20/0x3d mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:437 [inline]
____kasan_kmalloc mm/kasan/common.c:516 [inline]
__kasan_kmalloc+0x88/0xa3 mm/kasan/common.c:525
kasan_kmalloc include/linux/kasan.h:234 [inline]
__kmalloc+0x138/0x257 mm/slub.c:4429
kmalloc include/linux/slab.h:605 [inline]
ubi_alloc_vid_buf drivers/mtd/ubi/ubi.h:1093 [inline]
create_vtbl+0xcc/0x9c4 drivers/mtd/ubi/vtbl.c:295
create_empty_lvol drivers/mtd/ubi/vtbl.c:500 [inline]
ubi_read_volume_table+0x67b/0x288a drivers/mtd/ubi/vtbl.c:812
ubi_attach+0xf34/0x1603 drivers/mtd/ubi/attach.c:1601
ubi_attach_mtd_dev+0x6f3/0x185e drivers/mtd/ubi/build.c:965
ctrl_cdev_ioctl+0x2db/0x347 drivers/mtd/ubi/cdev.c:1043
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x213 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3e/0x86 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0x0
The buggy address belongs to the object at ffff88802bb36e00
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 0 bytes to the right of
256-byte region [ffff88802bb36e00, ffff88802bb36f00)
The buggy address belongs to the physical page:
page:00000000ea4d1263 refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x2bb36
head:00000000ea4d1263 order:1 compound_mapcount:0 compound_pincount:0
flags: 0xfffffc0010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0010200 ffffea000066c300 dead000000000003 ffff888100042b40
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88802bb36e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88802bb36e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88802bb36f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88802bb36f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88802bb37000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Fixes: 801c135ce73d ("UBI: Unsorted Block Images")
Reported-by: syzkaller <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: George Kennedy <george.kennedy@xxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/mtd/ubi/build.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 4153e0d15c5f9..8747569e793d4 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -664,6 +664,12 @@ static int io_init(struct ubi_device *ubi, int max_beb_per1024)
ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
+ if (ubi->vid_hdr_offset && ((ubi->vid_hdr_offset + UBI_VID_HDR_SIZE) >
+ ubi->vid_hdr_alsize)) {
+ ubi_err(ubi, "VID header offset %d too large.", ubi->vid_hdr_offset);
+ return -EINVAL;
+ }
+
dbg_gen("min_io_size %d", ubi->min_io_size);
dbg_gen("max_write_size %d", ubi->max_write_size);
dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
--
2.39.2
