From: Andreas Reichel <[email protected]> If a non-existing user variable is requested and a NULL-buffer is provided, the getter maps an invalid memory area to retrieve the needed buffer size. Fix this by checking if the data pointer is valid first before mapping anything and furthermore don't call the mapper if the variable is not found.
Signed-off-by: Andreas Reichel <[email protected]> --- env/env_api_fat.c | 3 +++ env/uservars.c | 16 +++++++++++++--- include/uservars.h | 6 +++--- 3 files changed, 19 insertions(+), 6 deletions(-) diff --git a/env/env_api_fat.c b/env/env_api_fat.c index 1705cb9..a86c05d 100644 --- a/env/env_api_fat.c +++ b/env/env_api_fat.c @@ -287,6 +287,9 @@ int bgenv_get(BGENV *env, char *key, uint64_t *type, void *data, uint8_t *u; uint32_t size; u = bgenv_find_uservar(env->data->userdata, key); + if (!u) { + return -EINVAL; + } bgenv_map_uservar(u, NULL, NULL, NULL, NULL, &size); return size; } diff --git a/env/uservars.c b/env/uservars.c index eff1cf8..3ad95c3 100644 --- a/env/uservars.c +++ b/env/uservars.c @@ -14,8 +14,8 @@ #include "env_api.h" #include "uservars.h" -void bgenv_map_uservar(uint8_t *udata, char **key, uint64_t *type, uint8_t **val, - uint32_t *record_size, uint32_t *data_size) +int bgenv_map_uservar(uint8_t *udata, char **key, uint64_t *type, uint8_t **val, + uint32_t *record_size, uint32_t *data_size) { /* Each user variable is encoded as follows: * |------------|--------------|---------------|----------------| @@ -38,6 +38,10 @@ void bgenv_map_uservar(uint8_t *udata, char **key, uint64_t *type, uint8_t **val uint64_t *var_type; uint8_t *data; + if (!udata) { + return -EINVAL; + } + /* Get the key */ var_key = (char *)udata; if (key) { @@ -68,6 +72,8 @@ void bgenv_map_uservar(uint8_t *udata, char **key, uint64_t *type, uint8_t **val if (val) { *val = data; } + + return 0; } void bgenv_serialize_uservar(uint8_t *p, char *key, uint64_t type, void *data, @@ -100,6 +106,7 @@ int bgenv_get_uservar(uint8_t *udata, char *key, uint64_t *type, void *data, char *lkey; uint32_t dsize; uint64_t ltype; + int res; uservar = bgenv_find_uservar(udata, key); @@ -107,7 +114,10 @@ int bgenv_get_uservar(uint8_t *udata, char *key, uint64_t *type, void *data, return -EINVAL; } - bgenv_map_uservar(uservar, &lkey, <ype, &value, NULL, &dsize); + res = bgenv_map_uservar(uservar, &lkey, <ype, &value, NULL, &dsize); + if (res) { + return res; + } if (dsize > maxlen) { dsize = maxlen; diff --git a/include/uservars.h b/include/uservars.h index b1d1d7c..012240c 100644 --- a/include/uservars.h +++ b/include/uservars.h @@ -15,9 +15,9 @@ #include <stdint.h> -void bgenv_map_uservar(uint8_t *udata, char **key, uint64_t *type, - uint8_t **val, uint32_t *record_size, - uint32_t *data_size); +int bgenv_map_uservar(uint8_t *udata, char **key, uint64_t *type, + uint8_t **val, uint32_t *record_size, + uint32_t *data_size); void bgenv_serialize_uservar(uint8_t *p, char *key, uint64_t type, void *data, uint32_t record_size); -- 2.17.0 -- You received this message because you are subscribed to the Google Groups "EFI Boot Guard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/efibootguard-dev/20180427124445.5059-2-andreas.reichel.ext%40siemens.com. For more options, visit https://groups.google.com/d/optout.
