From patchwork Tue May 26 19:06:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heinrich Schuchardt X-Patchwork-Id: 246637 List-Id: U-Boot discussion From: xypron.glpk at gmx.de (Heinrich Schuchardt) Date: Tue, 26 May 2020 21:06:50 +0200 Subject: [PATCH 1/1] fs: fat_write: fix short name creation. Message-ID: <20200526190650.22968-1-xypron.glpk@gmx.de> Truncate file names if the buffer size is exceeded to avoid a buffer overflow. Use Sphinx style function description. Add a TODO comment. Reported-by: CID 303779 Signed-off-by: Heinrich Schuchardt Reviewed-by: Simon Glass --- fs/fat/fat_write.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) -- 2.26.2 diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c index 59cc0bae94..b16a39d3ff 100644 --- a/fs/fat/fat_write.c +++ b/fs/fat/fat_write.c @@ -50,8 +50,11 @@ static int disk_write(__u32 block, __u32 nr_blocks, void *buf) return ret; } -/* - * Set short name in directory entry +/** + * set_name() - set short name in directory entry + * + * @dirent: directory entry + * @filename: long file name */ static void set_name(dir_entry *dirent, const char *filename) { @@ -66,7 +69,8 @@ static void set_name(dir_entry *dirent, const char *filename) if (len == 0) return; - strcpy(s_name, filename); + strncpy(s_name, filename, VFAT_MAXLEN_BYTES - 1); + s_name[VFAT_MAXLEN_BYTES - 1] = '\0'; uppercase(s_name, len); period = strchr(s_name, '.'); @@ -87,6 +91,11 @@ static void set_name(dir_entry *dirent, const char *filename) memcpy(dirent->name, s_name, period_location); } else { memcpy(dirent->name, s_name, 6); + /* + * TODO: Translating two long names with the same first six + * characters to the same short name is utterly wrong. + * Short names must be unique. + */ dirent->name[6] = '~'; dirent->name[7] = '1'; }