5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pengpeng Hou <redacted>
commit e9290031f736e99ad17c25c00311c92c266843b7 upstream.
The AFS v2 parser uses footer[8] to locate the image information block
inside the current erase block, then uses the image information
region_count to walk entries from a fixed local array. The footer offset
and region count come from flash contents and are not checked against the
erase block or the local image-info array before use.
Reject v2 entries whose image information offset would underflow the
erase block calculation, and reject region counts that cannot fit in the
local image-info array before walking region entries.
Fixes: b7cf5e2830bb ("mtd: afs: add v2 partition parsing")
Cc: <redacted>
Signed-off-by: Pengpeng Hou <redacted>
Acked-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/mtd/parsers/afs.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/drivers/mtd/parsers/afs.c
+++ b/drivers/mtd/parsers/afs.c
@@ -235,6 +235,9 @@ static int afs_parse_v2_partition(struct
pr_debug("Parsing v2 partition @%08x-%08x\n",
off, off + mtd->erasesize);
+ if (mtd->erasesize < sizeof(footer))
+ return -EINVAL;
+
/* First read the footer */
ptr = off + mtd->erasesize - sizeof(footer);
ret = mtd_read(mtd, ptr, sizeof(footer), &sz, (u_char *)footer);@@ -245,6 +248,8 @@ static int afs_parse_v2_partition(struct
}
name = (char *) &footer[0];
version = footer[9];
+ if (footer[8] > mtd->erasesize - sizeof(footer))
+ return -EINVAL;
ptr = off + mtd->erasesize - sizeof(footer) - footer[8];
pr_debug("found image \"%s\", version %08x, info @%08x\n",@@ -278,6 +283,8 @@ static int afs_parse_v2_partition(struct
entrypoint = imginfo[pad];
attributes = imginfo[pad+1];
region_count = imginfo[pad+2];
+ if (region_count > (ARRAY_SIZE(imginfo) - pad - 3) / 4)
+ return -EINVAL;
block_start = imginfo[20];
block_end = imginfo[21];