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| author |   Mike Frysinger <vapier@gentoo.org> | 2009-03-04 23:43:28 -0500 |
|---|---|---|
| committer | Mike Frysinger <vapier@gentoo.org> | 2009-03-04 23:43:28 -0500 |
| commit | aad0a25b8708a06171a4703a2f28d7da68be78c7 (patch) | |
| tree | bb77bf4c03059cb5270ba9995193d5d3269ffe35 /libsandbox/wrappers.c | |
| parent | libsandbox: unify openat and __wrapper_simple (diff) | |
| download | sandbox-aad0a25b8708a06171a4703a2f28d7da68be78c7.tar.gz sandbox-aad0a25b8708a06171a4703a2f28d7da68be78c7.tar.bz2 sandbox-aad0a25b8708a06171a4703a2f28d7da68be78c7.zip | |
libsandbox: save/restore errno for hardenedv1.3.9
Since hardened systems may return -1 in the case of an error, but this
isn't a "real" error, we need to save/restore errno. Otherwise we corrupt
the errno value of the caller. This is a regression on hardened systems
due to the recent commit bab59e2c which optimized symbol loading a bit.
URL: http://bugs.gentoo.org/260765
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Reported-by: Magnus Granberg <zorry@ume.nu>
Diffstat (limited to 'libsandbox/wrappers.c')
| -rw-r--r-- | libsandbox/wrappers.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/libsandbox/wrappers.c b/libsandbox/wrappers.c index 29bd9d4..6094f51 100644 --- a/libsandbox/wrappers.c +++ b/libsandbox/wrappers.c @@ -32,10 +32,13 @@ static void *get_dlsym(const char *symname, const char *symver) /* Checking for -1UL is significant on hardened! * USE_RTLD_NEXT returns it as a sign of being unusable. * However using !x or NULL checks does NOT pick it up! + * That is also why we need to save/restore errno #260765. */ #define INVALID_LIBC_HANDLE(x) (!x || NULL == x || (void *)-1UL == x) if (INVALID_LIBC_HANDLE(libc_handle)) { + save_errno(); libc_handle = dlopen(LIBC_VERSION, RTLD_LAZY); + restore_errno(); if (INVALID_LIBC_HANDLE(libc_handle)) { fprintf(stderr, "libsandbox: Can't dlopen libc: %s\n", dlerror()); @@ -48,6 +51,7 @@ static void *get_dlsym(const char *symname, const char *symver) symaddr = dlsym(libc_handle, symname); else symaddr = dlvsym(libc_handle, symname, symver); + if (!symaddr) { fprintf(stderr, "libsandbox: Can't resolve %s: %s\n", symname, dlerror()); |