diff options
| author | Marcel Apfelbaum <marcel@redhat.com> | 2018-01-08 23:50:07 +0200 |
|---|---|---|
| committer | Eduardo Habkost <ehabkost@redhat.com> | 2018-01-19 11:18:51 -0200 |
| commit | d6b6abc51dda79a97f2c7bd6652c1940c068f1ec (patch) | |
| tree | bbd0e7a39efd262c9196edea6d75a88d47557d8a /hw/nvram | |
| parent | d342eb7662bcfe47c26615b67025ae59a383489d (diff) | |
fw_cfg: fix memory corruption when all fw_cfg slots are used
When all the fw_cfg slots are used, a write is made outside the
bounds of the fw_cfg files array as part of the sort algorithm.
Fix it by avoiding an unnecessary array element move.
Fix also an assert while at it.
Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Message-Id: <20180108215007.46471-1-marcel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Diffstat (limited to 'hw/nvram')
| -rw-r--r-- | hw/nvram/fw_cfg.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index 753ac0e4ea..4313484b21 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -784,7 +784,7 @@ void fw_cfg_add_file_callback(FWCfgState *s, const char *filename, * index and "i - 1" is the one being copied from, thus the * unusual start and end in the for statement. */ - for (i = count + 1; i > index; i--) { + for (i = count; i > index; i--) { s->files->f[i] = s->files->f[i - 1]; s->files->f[i].select = cpu_to_be16(FW_CFG_FILE_FIRST + i); s->entries[0][FW_CFG_FILE_FIRST + i] = @@ -833,7 +833,6 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, assert(s->files); index = be32_to_cpu(s->files->count); - assert(index < fw_cfg_file_slots(s)); for (i = 0; i < index; i++) { if (strcmp(filename, s->files->f[i].name) == 0) { @@ -843,6 +842,9 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, return ptr; } } + + assert(index < fw_cfg_file_slots(s)); + /* add new one */ fw_cfg_add_file_callback(s, filename, NULL, NULL, NULL, data, len, true); return NULL; |