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 <[email protected]> --- Changes in v2: - Verify required arguments in a more flexible way drivers/md/dm-pcache/dm_pcache.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/md/dm-pcache/dm_pcache.c b/drivers/md/dm-pcache/dm_pcache.c index 81c795c0400e..d5cfd162c063 100644 --- a/drivers/md/dm-pcache/dm_pcache.c +++ b/drivers/md/dm-pcache/dm_pcache.c @@ -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; -- 2.43.0
