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author | Johannes Berg <johannes@sipsolutions.net> | 2007-05-08 00:27:20 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 11:15:05 -0700 |
commit | c6b40d16d1cfa1a01158049bb887a9bbe48ef7ba (patch) | |
tree | 72eac6e26f928780fe722ad45ff6eeb6807d2356 | |
parent | 757dea93e136b219af09d3cd56a81063fdbdef1a (diff) | |
download | linux-c6b40d16d1cfa1a01158049bb887a9bbe48ef7ba.tar.bz2 |
fix sscanf %n match at end of input string
I was playing with some code that sometimes got a string where a %n
match should have been done where the input string ended, for example
like this:
sscanf("abc123", "abc%d%n", &a, &n); /* doesn't work */
sscanf("abc123a", "abc%d%n", &a, &n); /* works */
However, the scanf function in the kernel doesn't convert the %n in that
case because it has already matched the complete input after %d and just
completely stops matching then. This patch fixes that.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | lib/vsprintf.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index cbab1df150cf..017290241261 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -825,6 +825,17 @@ int vsscanf(const char * buf, const char * fmt, va_list args) break; str = next; } + + /* + * Now we've come all the way through so either the input string or the + * format ended. In the former case, there can be a %n at the current + * position in the format that needs to be filled. + */ + if (*fmt == '%' && *(fmt + 1) == 'n') { + int *p = (int *)va_arg(args, int *); + *p = str - buf; + } + return num; } |