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| author | Rich Felker <dalias@aerifal.cx> | 2013-09-29 02:52:33 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2013-09-29 02:52:33 -0400 |
| commit | 23b8e3bc95620b0bd90a78ce0d926942c12b45da (patch) | |
| tree | b4ef44467f7890cb88a56d939d2d19e6bd2c7643 | |
| parent | 211264e46a2f1bc382a84435e904d1548de672b0 (diff) | |
| download | musl-23b8e3bc95620b0bd90a78ce0d926942c12b45da.tar.gz musl-23b8e3bc95620b0bd90a78ce0d926942c12b45da.tar.xz musl-23b8e3bc95620b0bd90a78ce0d926942c12b45da.zip | |
fix off-by-one error in getgrnam_r and getgrgid_r, clobbering gr_name
bug report and patch by Michael Forney. the terminating null pointer at the end of the gr_mem array was overwriting the beginning of the string data, causing the gr_name member to always be a zero-length string.
| -rw-r--r-- | src/passwd/getgr_r.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/passwd/getgr_r.c b/src/passwd/getgr_r.c index 234c9013..3fe2e2b2 100644 --- a/src/passwd/getgr_r.c +++ b/src/passwd/getgr_r.c @@ -26,14 +26,14 @@ static int getgr_r(const char *name, gid_t gid, struct group *gr, char *buf, siz while (__getgrent_a(f, gr, &line, &len, &mem, &nmem)) { if (name && !strcmp(name, gr->gr_name) || !name && gr->gr_gid == gid) { - if (size < len + nmem*sizeof(char *) + 32) { + if (size < len + (nmem+1)*sizeof(char *) + 32) { rv = ERANGE; break; } *res = gr; buf += (16-(uintptr_t)buf)%16; gr->gr_mem = (void *)buf; - buf += nmem*sizeof(char *); + buf += (nmem+1)*sizeof(char *); memcpy(buf, line, len); FIX(name); FIX(passwd); |