On Mon, Jun 29, 2026 at 11:48 PM Samuel Moelius <[email protected]> wrote: > > 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 >
Reviewed-by: Zheng Gu <[email protected]>
