diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2014-03-23 00:28:40 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-04-03 12:02:36 -0700 |
| commit | fa82051f97c1e81e44ae1517a4303db6ceba1e2b (patch) | |
| tree | 7577b51903b553991dba123d3d21f21e0bf90338 | |
| parent | abfabd98494dcba8cefe726a28c006be87b34d0c (diff) | |
make prepend_name() work correctly when called with negative *buflen
commit e825196d48d2b89a6ec3a8eff280098d2a78207e upstream.
In all callchains leading to prepend_name(), the value left in *buflen
is eventually discarded unused if prepend_name() has returned a negative.
So we are free to do what prepend() does, and subtract from *buflen
*before* checking for underflow (which turns into checking the sign
of subtraction result, of course).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/dcache.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index fdbe23027810..f7ad6d71b1c1 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2833,9 +2833,9 @@ static int prepend_name(char **buffer, int *buflen, struct qstr *name) u32 dlen = ACCESS_ONCE(name->len); char *p; - if (*buflen < dlen + 1) - return -ENAMETOOLONG; *buflen -= dlen + 1; + if (*buflen < 0) + return -ENAMETOOLONG; p = *buffer -= dlen + 1; *p++ = '/'; while (dlen--) { |