From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Subject: proc: reject "." and ".." as filenames Various subsystems can create files and directories in /proc with names directly controlled by userspace. Which means "/", "." and ".." are no-no. "/" split is already taken care of, do the other 2 prohibited names. Link: http://lkml.kernel.org/r/20180310001223.GB12443@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Acked-by: Florian Westphal <fw@xxxxxxxxx> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx> Cc: Cong Wang <xiyou.wangcong@xxxxxxxxx> Cc: Pavel Machek <pavel@xxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/generic.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff -puN fs/proc/generic.c~proc-reject-and-as-filenames fs/proc/generic.c --- a/fs/proc/generic.c~proc-reject-and-as-filenames +++ a/fs/proc/generic.c @@ -366,6 +366,14 @@ static struct proc_dir_entry *__proc_cre WARN(1, "name len %u\n", qstr.len); return NULL; } + if (qstr.len == 1 && fn[0] == '.') { + WARN(1, "name '.'\n"); + return NULL; + } + if (qstr.len == 2 && fn[0] == '.' && fn[1] == '.') { + WARN(1, "name '..'\n"); + return NULL; + } if (*parent == &proc_root && name_to_int(&qstr) != ~0U) { WARN(1, "create '/proc/%s' by hand\n", qstr.name); return NULL; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
