Re: [PATCH v2] libnsm: fix the safer atomic filenames fix
From: Steve Dickson <hidden>
Date: 2024-11-30 13:11:55
On 11/27/24 6:44 AM, Benjamin Coddington wrote:
Commit 9f7a91b51ffc ("libnsm: safer atomic filenames") messed up the length
arguement to snprintf() in nsm_make_temp_pathname such that the length is
longer than the computed string. When compiled with "-O
-D_FORTIFY_SOURCE=3", __snprintf_chk will fail and abort statd.
The fix is to correct the original size calculation, then pull one from the
snprintf length for the final "/".
Fixes: 9f7a91b51ffc ("libnsm: safer atomic filenames")
Signed-off-by: Benjamin Coddington <redacted>Reverted and Committed.... steved.
quoted hunk ↗ jump to hunk
--- v2: ensure we handle paths without '/', simplify. --- support/nsm/file.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)diff --git a/support/nsm/file.c b/support/nsm/file.c index e0804136ccbe..de122b0fc5a1 100644 --- a/support/nsm/file.c +++ b/support/nsm/file.c@@ -187,7 +187,7 @@ nsm_make_temp_pathname(const char *pathname) char *path, *base; int len; - size = strlen(pathname) + sizeof(".new") + 3; + size = strlen(pathname) + sizeof(".new") + 1; if (size > PATH_MAX) return NULL;@@ -196,15 +196,19 @@ nsm_make_temp_pathname(const char *pathname) return NULL; base = strrchr(pathname, '/'); - strcpy(path, pathname); + if (base == NULL) + base = pathname; + else + base++; + strcpy(path, pathname); len = base - pathname; - len += snprintf(path + len + 1, size-len, ".%s.new", base+1); + len += snprintf(path + len, size - len, ".%s.new", base); + if (error_check(len, size)) { free(path); return NULL; } - return path; }base-commit: eb5abb5c60ab60f3c2f22518d513ed187f39bd9b