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author | jilles <jilles@FreeBSD.org> | 2016-01-27 22:56:04 +0000 |
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committer | jilles <jilles@FreeBSD.org> | 2016-01-27 22:56:04 +0000 |
commit | 42ee9ca9933fb815ce7d9098f10bad6fe38c69b4 (patch) | |
tree | 6566abe70454f4bb516d4bc56029438a4af29a18 | |
parent | 3e03b75dcaf65a439918ff675adb4717c6c13c6c (diff) | |
download | FreeBSD-src-42ee9ca9933fb815ce7d9098f10bad6fe38c69b4.zip FreeBSD-src-42ee9ca9933fb815ce7d9098f10bad6fe38c69b4.tar.gz |
MFC r294565: sem: Don't free nameinfo that is still in list when open()
fails.
This bug could be reproduced easily by calling sem_open() with O_CREAT |
O_EXCL on a semaphore that is already open in the process. The struct
sem_nameinfo would be freed while still in sem_list and later calls to
sem_open() or sem_close() could access freed memory.
PR: 206396
-rw-r--r-- | lib/libc/gen/sem_new.c | 4 | ||||
-rw-r--r-- | tools/regression/posixsem2/semtest.c | 35 |
2 files changed, 38 insertions, 1 deletions
diff --git a/lib/libc/gen/sem_new.c b/lib/libc/gen/sem_new.c index 7b04ef0..243ceba 100644 --- a/lib/libc/gen/sem_new.c +++ b/lib/libc/gen/sem_new.c @@ -176,8 +176,10 @@ _sem_open(const char *name, int flags, ...) if (ni->name != NULL && strcmp(name, ni->name) == 0) { fd = _open(path, flags | O_RDWR | O_CLOEXEC | O_EXLOCK, mode); - if (fd == -1 || _fstat(fd, &sb) == -1) + if (fd == -1 || _fstat(fd, &sb) == -1) { + ni = NULL; goto error; + } if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL) || ni->dev != sb.st_dev || ni->ino != sb.st_ino) { diff --git a/tools/regression/posixsem2/semtest.c b/tools/regression/posixsem2/semtest.c index b1255db..0879ff9 100644 --- a/tools/regression/posixsem2/semtest.c +++ b/tools/regression/posixsem2/semtest.c @@ -7,6 +7,7 @@ #include <stdio.h> #include <stdlib.h> #include <err.h> +#include <errno.h> #include <fcntl.h> #include <unistd.h> @@ -14,6 +15,7 @@ int test_unnamed(void); int test_named(void); +int test_named2(void); int test_unnamed(void) @@ -94,9 +96,42 @@ test_named(void) } int +test_named2(void) +{ + sem_t *s, *s2, *s3; + + printf("testing named process-shared semaphore, O_EXCL cases\n"); + sem_unlink(SEM_NAME); + s = sem_open(SEM_NAME, O_CREAT | O_EXCL, 0777, 0); + if (s == SEM_FAILED) + err(1, "sem_open failed"); + s2 = sem_open(SEM_NAME, O_CREAT | O_EXCL, 0777, 0); + if (s2 != SEM_FAILED) + errx(2, "second sem_open call wrongly succeeded"); + if (errno != EEXIST) + err(3, "second sem_open call failed with wrong errno"); + + s3 = sem_open(SEM_NAME, 0); + if (s3 == SEM_FAILED) + err(4, "third sem_open call failed"); + if (s != s3) + errx(5, +"two sem_open calls for same semaphore do not return same address"); + if (sem_close(s3)) + err(6, "sem_close failed"); + + if (sem_close(s)) + err(7, "sem_close failed"); + + printf("OK.\n"); + return (0); +} + +int main(void) { test_unnamed(); test_named(); + test_named2(); return (0); } |