mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-22 03:27:30 -04:00
Code Issues Packages Projects Releases Wiki Activity

dm-pcache: reject option groups without values

Browse Source 
The pcache target parses optional arguments as name/value pairs.  A
table that advertises one optional argument and supplies only a
recognized option name, for example "cache_mode", reaches
parse_cache_opts() with argc == 1.  The parser consumes the name,
decrements argc to zero, then calls dm_shift_arg() again for the value.
dm_shift_arg() returns NULL when no arguments remain, and the following
strcmp() dereferences that NULL pointer.

Check that each recognized option has a value before consuming it.  This
keeps valid "cache_mode writeback" and "data_crc true/false" tables
unchanged while making malformed tables fail during target construction
with a precise missing-value error.

Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
Reviewed-by:  Zheng Gu <cengku@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 1d57628ff9 ("dm-pcache: add persistent cache target in device-mapper")
Cc: stable@vger.kernel.org
This commit is contained in:
Samuel Moelius
2026-06-29 15:47:40 +00:00
committed by Mikulas Patocka
parent 5bcd4d3058
commit d9c631e3fb
1 changed files with 8 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/md/dm-pcache/dm_pcache.c
View File

@@ -168,6 +168,10 @@ static int parse_cache_opts(struct dm_pcache *pcache, struct dm_arg_set *as,
argc--;
if (!strcmp(arg, "cache_mode")) {
if (!argc) {
*error = "Missing value for cache_mode";
return -EINVAL;
}
arg = dm_shift_arg(as);
if (!strcmp(arg, "writeback")) {
opts->cache_mode = PCACHE_CACHE_MODE_WRITEBACK;
@@ -177,6 +181,10 @@ static int parse_cache_opts(struct dm_pcache *pcache, struct dm_arg_set *as,
}
argc--;
} else if (!strcmp(arg, "data_crc")) {
if (!argc) {
*error = "Missing value for data_crc";
return -EINVAL;
}
arg = dm_shift_arg(as);
if (!strcmp(arg, "true")) {
opts->data_crc = true;