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| author | Joseph Myers <joseph@codesourcery.com> | 2017-12-18 18:50:40 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2017-12-18 18:50:40 +0000 |
| commit | 49b036bce9f021ae994a85aee8b410d20b29c8b7 (patch) | |
| tree | f0100e6d1378252d9cb40f96982b245ab69a657c | |
| parent | c85c564d1442f0bc09a6c80fca025f004e12d044 (diff) | |
| download | glibc-49b036bce9f021ae994a85aee8b410d20b29c8b7.zip glibc-49b036bce9f021ae994a85aee8b410d20b29c8b7.tar.gz glibc-49b036bce9f021ae994a85aee8b410d20b29c8b7.tar.bz2 | |
Fix nscd readlink argument aliasing (bug 22446).
Current GCC mainline detects that nscd calls readlink with the same
buffer for both input and output, which is not valid (those arguments
are both restrict-qualified in POSIX). This patch makes it use a
separate buffer for readlink's input (with a size that is sufficient
to avoid truncation, so there should be no problems with warnings
about possible truncation, though not strictly minimal, but much
smaller than the buffer for output) to avoid this problem.
Tested compilation for aarch64-linux-gnu with build-many-glibcs.py.
[BZ #22446]
* nscd/connections.c (handle_request) [SO_PEERCRED]: Use separate
buffers for readlink input and output.
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | nscd/connections.c | 5 |
2 files changed, 9 insertions, 2 deletions
@@ -1,3 +1,9 @@ +2017-12-18 Joseph Myers <joseph@codesourcery.com> + + [BZ #22446] + * nscd/connections.c (handle_request) [SO_PEERCRED]: Use separate + buffers for readlink input and output. + 2017-12-18 Sergei Trofimovich <slyfox@gentoo.org> [BZ #22624] diff --git a/nscd/connections.c b/nscd/connections.c index cc1ed72..dab722d 100644 --- a/nscd/connections.c +++ b/nscd/connections.c @@ -1077,14 +1077,15 @@ cannot handle old request version %d; current version is %d"), if (debug_level > 0) { #ifdef SO_PEERCRED + char pbuf[sizeof ("/proc//exe") + 3 * sizeof (long int)]; # ifdef PATH_MAX char buf[PATH_MAX]; # else char buf[4096]; # endif - snprintf (buf, sizeof (buf), "/proc/%ld/exe", (long int) pid); - ssize_t n = readlink (buf, buf, sizeof (buf) - 1); + snprintf (pbuf, sizeof (pbuf), "/proc/%ld/exe", (long int) pid); + ssize_t n = readlink (pbuf, buf, sizeof (buf) - 1); if (n <= 0) dbg_log (_("\ |