diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2014-03-23 00:28:40 -0400 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-04-03 10:32:29 +0200 |
| commit | a41fd7536d9cbc81cf02033c3efa4078431fa4d0 (patch) | |
| tree | 24c826b660b08f78a65b20ec46b807a26b9f849e | |
| parent | 2c611dc0ca77c8012fee6f33cf05040b16dbee38 (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: Jiri Slaby <jslaby@suse.cz>
| -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 4021e0172602..30b38e23caa7 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2846,9 +2846,9 @@ 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--) { |