diff options
| author | Patrick Wildt <patrick@blueri.se> | 2018-11-26 15:56:57 +0100 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2018-12-06 23:26:31 -0500 |
| commit | cd80a4fe611d7cb4153a6ed39d1e5052c702fb12 (patch) | |
| tree | bb1f596d2c8e74a0744c6999159ab293cf07a50a /fs | |
| parent | 16462a35728039aa173a02982643c551dc94ba20 (diff) | |
fs: check FAT cluster size
The cluster size specifies how many sectors make up a cluster. A
cluster size of zero makes no sense, as it would mean that the
cluster is made up of no sectors. This will later lead into a
division by zero in sect_to_clust(), so better take care of that
early.
The MAX_CLUSTSIZE define can reduced using a define to make some
room in low-memory system. Unfortunately if the code reads a
filesystem with a bigger cluster size it will overflow the buffer.
Signed-off-by: Patrick Wildt <patrick@blueri.se>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/fat/fat.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/fat/fat.c b/fs/fat/fat.c index 4bc3030ab8..e0c076763f 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -571,6 +571,17 @@ static int get_fs_info(fsdata *mydata) mydata->sect_size, cur_part_info.blksz); return -1; } + if (mydata->clust_size == 0) { + printf("Error: FAT cluster size not set\n"); + return -1; + } + if ((unsigned int)mydata->clust_size * mydata->sect_size > + MAX_CLUSTSIZE) { + printf("Error: FAT cluster size too big (cs=%u, max=%u)\n", + (unsigned int)mydata->clust_size * mydata->sect_size, + MAX_CLUSTSIZE); + return -1; + } if (mydata->fatsize == 32) { mydata->data_begin = mydata->rootdir_sect - |