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author | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2017-03-07 20:52:04 +0530 |
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committer | Siddhesh Poyarekar <siddhesh@sourceware.org> | 2017-03-07 20:52:04 +0530 |
commit | 1c1243b6fc33c029488add276e56570a07803bfd (patch) | |
tree | dc024978a5a16a4bd027a4f28508ab503983fa6c /elf/rtld.c | |
parent | a7055e5935f7ee63d622c66a7dde16ba0de674e0 (diff) | |
download | glibc-1c1243b6fc33c029488add276e56570a07803bfd.tar.gz glibc-1c1243b6fc33c029488add276e56570a07803bfd.tar.xz glibc-1c1243b6fc33c029488add276e56570a07803bfd.zip |
Ignore and remove LD_HWCAP_MASK for AT_SECURE programs (bug #21209)
The LD_HWCAP_MASK environment variable may alter the selection of function variants for some architectures. For AT_SECURE process it means that if an outdated routine has a bug that would otherwise not affect newer platforms by default, LD_HWCAP_MASK will allow that bug to be exploited. To be on the safe side, ignore and disable LD_HWCAP_MASK for setuid binaries. [BZ #21209] * elf/rtld.c (process_envvars): Ignore LD_HWCAP_MASK for AT_SECURE processes. * sysdeps/generic/unsecvars.h: Add LD_HWCAP_MASK. * elf/tst-env-setuid.c (test_parent): Test LD_HWCAP_MASK. (test_child): Likewise. * elf/Makefile (tst-env-setuid-ENV): Add LD_HWCAP_MASK.
Diffstat (limited to 'elf/rtld.c')
-rw-r--r-- | elf/rtld.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/elf/rtld.c b/elf/rtld.c index a036ece956..5986eaf4a1 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -2404,7 +2404,8 @@ process_envvars (enum mode *modep) case 10: /* Mask for the important hardware capabilities. */ - if (memcmp (envline, "HWCAP_MASK", 10) == 0) + if (!__libc_enable_secure + && memcmp (envline, "HWCAP_MASK", 10) == 0) GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL, 0, 0); break; |