diff options
| author | Geert Uytterhoeven <geert@linux-m68k.org> | 2012-09-29 22:23:19 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-31 09:51:35 -0700 |
| commit | e17ce2ec38fd766e8f9707701e47f4332d8bb630 (patch) | |
| tree | 609a59ea45aff2c2a71f4046e5801c84b49ab7f3 /fs | |
| parent | 910e425b29da7b601a99f49e81da666ab8ed5920 (diff) | |
sysfs: sysfs_pathname/sysfs_add_one: Use strlcat() instead of strcat()
commit 66081a72517a131430dcf986775f3268aafcb546 upstream.
The warning check for duplicate sysfs entries can cause a buffer overflow
when printing the warning, as strcat() doesn't check buffer sizes.
Use strlcat() instead.
Since strlcat() doesn't return a pointer to the passed buffer, unlike
strcat(), I had to convert the nested concatenation in sysfs_add_one() to
an admittedly more obscure comma operator construct, to avoid emitting code
for the concatenation if CONFIG_BUG is disabled.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/sysfs/dir.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index ea9120a830d8..567b3db70099 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -404,20 +404,18 @@ int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) /** * sysfs_pathname - return full path to sysfs dirent * @sd: sysfs_dirent whose path we want - * @path: caller allocated buffer + * @path: caller allocated buffer of size PATH_MAX * * Gives the name "/" to the sysfs_root entry; any path returned * is relative to wherever sysfs is mounted. - * - * XXX: does no error checking on @path size */ static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) { if (sd->s_parent) { sysfs_pathname(sd->s_parent, path); - strcat(path, "/"); + strlcat(path, "/", PATH_MAX); } - strcat(path, sd->s_name); + strlcat(path, sd->s_name, PATH_MAX); return path; } @@ -450,9 +448,11 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) char *path = kzalloc(PATH_MAX, GFP_KERNEL); WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s'\n", - (path == NULL) ? sd->s_name : - strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"), - sd->s_name)); + (path == NULL) ? sd->s_name + : (sysfs_pathname(acxt->parent_sd, path), + strlcat(path, "/", PATH_MAX), + strlcat(path, sd->s_name, PATH_MAX), + path)); kfree(path); } |