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| author | Li Zetao <lizetao1@huawei.com> | 2022-10-21 13:21:56 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-11 18:44:09 +0300 |
| commit | 9c8be1f165baee53b5a36ea0b3c9281d403a1d0b (patch) | |
| tree | 2ed03b409104fcc1a30ef8ff9cb92ece2f8b658c /drivers/mtd/ubi/vmt.c | |
| parent | e86d1b2bb71611671f4f8d99e548c55e6a0a747d (diff) | |
| download | linux-9c8be1f165baee53b5a36ea0b3c9281d403a1d0b.tar.xz | |
ubi: Fix use-after-free when volume resizing failed
[ Upstream commit 9af31d6ec1a4be4caab2550096c6bd2ba8fba472 ]
There is an use-after-free problem reported by KASAN:
==================================================================
BUG: KASAN: use-after-free in ubi_eba_copy_table+0x11f/0x1c0 [ubi]
Read of size 8 at addr ffff888101eec008 by task ubirsvol/4735
CPU: 2 PID: 4735 Comm: ubirsvol
Not tainted 6.1.0-rc1-00003-g84fa3304a7fc-dirty #14
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.14.0-1.fc33 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
print_report+0x171/0x472
kasan_report+0xad/0x130
ubi_eba_copy_table+0x11f/0x1c0 [ubi]
ubi_resize_volume+0x4f9/0xbc0 [ubi]
ubi_cdev_ioctl+0x701/0x1850 [ubi]
__x64_sys_ioctl+0x11d/0x170
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
</TASK>
When ubi_change_vtbl_record() returns an error in ubi_resize_volume(),
"new_eba_tbl" will be freed on error handing path, but it is holded
by "vol->eba_tbl" in ubi_eba_replace_table(). It means that the liftcycle
of "vol->eba_tbl" and "vol" are different, so when resizing volume in
next time, it causing an use-after-free fault.
Fix it by not freeing "new_eba_tbl" after it replaced in
ubi_eba_replace_table(), while will be freed in next volume resizing.
Fixes: 801c135ce73d ("UBI: Unsorted Block Images")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/mtd/ubi/vmt.c')
| -rw-r--r-- | drivers/mtd/ubi/vmt.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index 6ea95ade4ca6..6c7822c1cc45 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -464,7 +464,7 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) for (i = 0; i < -pebs; i++) { err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i); if (err) - goto out_acc; + goto out_free; } spin_lock(&ubi->volumes_lock); ubi->rsvd_pebs += pebs; @@ -512,6 +512,8 @@ out_acc: ubi->avail_pebs += pebs; spin_unlock(&ubi->volumes_lock); } + return err; + out_free: kfree(new_eba_tbl); return err; |