From 39a759494f734c4cdc3e2b919671bfb3134b41ae Mon Sep 17 00:00:00 2001 From: Paul Emge Date: Mon, 8 Jul 2019 16:37:03 -0700 Subject: [PATCH 1/9] CVE-2019-13103: disk: stop infinite recursion in DOS Partitions part_get_info_extended and print_partition_extended can recurse infinitely while parsing a self-referential filesystem or one with a silly number of extended partitions. This patch adds a limit to the number of recursive partitions. Signed-off-by: Paul Emge Upstream-Status: Backport[http://git.denx.de/?p=u-boot.git;a=commit; h=232e2f4fd9a24bf08215ddc8c53ccadffc841fb5] CVE: CVE-2019-13103 Signed-off-by: Meng Li --- disk/part_dos.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/disk/part_dos.c b/disk/part_dos.c index 936cee0d36..aae9d95906 100644 --- a/disk/part_dos.c +++ b/disk/part_dos.c @@ -23,6 +23,10 @@ #define DOS_PART_DEFAULT_SECTOR 512 +/* should this be configurable? It looks like it's not very common at all + * to use large numbers of partitions */ +#define MAX_EXT_PARTS 256 + /* Convert char[4] in little endian format to the host format integer */ static inline unsigned int le32_to_int(unsigned char *le32) @@ -126,6 +130,13 @@ static void print_partition_extended(struct blk_desc *dev_desc, dos_partition_t *pt; int i; + /* set a maximum recursion level */ + if (part_num > MAX_EXT_PARTS) + { + printf("** Nested DOS partitions detected, stopping **\n"); + return; + } + if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) { printf ("** Can't read partition table on %d:" LBAFU " **\n", dev_desc->devnum, ext_part_sector); @@ -191,6 +202,13 @@ static int part_get_info_extended(struct blk_desc *dev_desc, int i; int dos_type; + /* set a maximum recursion level */ + if (part_num > MAX_EXT_PARTS) + { + printf("** Nested DOS partitions detected, stopping **\n"); + return -1; + } + if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) { printf ("** Can't read partition table on %d:" LBAFU " **\n", dev_desc->devnum, ext_part_sector); -- 2.17.1