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authorLi Zetao <lizetao1@huawei.com>2022-10-21 13:21:56 +0300
committerRichard Weinberger <richard@nod.at>2023-02-02 23:13:41 +0300
commit9af31d6ec1a4be4caab2550096c6bd2ba8fba472 (patch)
tree834c9f06c8e16dc87aafc4250bc23fcce79a26a2 /drivers/mtd
parente874dcde1cbf82c786c0e7f2899811c02630cc52 (diff)
downloadlinux-9af31d6ec1a4be4caab2550096c6bd2ba8fba472.tar.xz
ubi: Fix use-after-free when volume resizing failed
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>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/ubi/vmt.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 8fcc0bdf0635..74637575346e 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;