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| author | Tobias Stoeckmann <tobias@stoeckmann.org> | 2016-06-18 18:41:07 +0200 |
|---|---|---|
| committer | Allan McRae <allan@archlinux.org> | 2016-08-30 18:10:40 +1000 |
| commit | 5fcd60e2641c9293c2783aad509baf217e77aa6f (patch) | |
| tree | 9b7d209b26e4eefae61276c047616b52da9c20e7 | |
| parent | 681509fd445ed6012e6ecf89b49e9c00d83b70cd (diff) | |
| download | pacman-5fcd60e2641c9293c2783aad509baf217e77aa6f.tar.xz | |
Reject files larger than 16384 bytes in read_sigfile.
If signature files are larger than SIZE_MAX, not enough memory could
be allocated for this file. The script repo-add rejects files which
are larger than 16384 bytes, therefore handle these as errors here,
too.
While at it, I also rearranged the code to avoid a quite harmless
TOCTOU race condition between stat() and fopen().
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Signed-off-by: Allan McRae <allan@archlinux.org>
| -rw-r--r-- | lib/libalpm/be_package.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/lib/libalpm/be_package.c b/lib/libalpm/be_package.c index a79c0c5b..430d2aeb 100644 --- a/lib/libalpm/be_package.c +++ b/lib/libalpm/be_package.c @@ -24,6 +24,7 @@ #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> +#include <limits.h> /* libarchive */ #include <archive.h> @@ -695,22 +696,25 @@ error: return NULL; } +/* adopted limit from repo-add */ +#define MAX_SIGFILE_SIZE 16384 + static int read_sigfile(const char *sigpath, unsigned char **sig) { struct stat st; FILE *fp; - if(stat(sigpath, &st) != 0) { + if((fp = fopen(sigpath, "rb")) == NULL) { return -1; } - MALLOC(*sig, st.st_size, return -1); - - if((fp = fopen(sigpath, "rb")) == NULL) { - free(*sig); + if(fstat(fileno(fp), &st) != 0 || st.st_size > MAX_SIGFILE_SIZE) { + fclose(fp); return -1; } + MALLOC(*sig, st.st_size, fclose(fp); return -1); + if(fread(*sig, st.st_size, 1, fp) != 1) { free(*sig); fclose(fp); |