diff options
author | Rich Felker <dalias@aerifal.cx> | 2015-05-06 18:37:19 -0400 |
---|---|---|
committer | Rich Felker <dalias@aerifal.cx> | 2015-05-06 18:37:19 -0400 |
commit | 484194dbf41758eec0ef62fef5fe9350c21b9241 (patch) | |
tree | d0b407880ba1c62f9fd3b551c6e9a9e745bd8cdd /arch | |
parent | d0040e239e8d3048a7fb38f0bacaad4838fac605 (diff) | |
download | musl-484194dbf41758eec0ef62fef5fe9350c21b9241.tar.gz |
fix stack protector crashes on x32 & powerpc due to misplaced TLS canary
i386, x86_64, x32, and powerpc all use TLS for stack protector canary
values in the default stack protector ABI, but the location only
matched the ABI on i386 and x86_64. on x32, the expected location for
the canary contained the tid, thus producing spurious mismatches
(resulting in process termination) upon fork. on powerpc, the expected
location contained the stdio_locks list head, so returning from a
function after calling flockfile produced spurious mismatches. in both
cases, the random canary was not present, and a predictable value was
used instead, making the stack protector hardening much less effective
than it should be.
in the current fix, the thread structure has been expanded to have
canary fields at all three possible locations, and archs that use a
non-default location must define a macro in pthread_arch.h to choose
which location is used. for most archs (which lack TLS canary ABI) the
choice does not matter.
Diffstat (limited to 'arch')
-rw-r--r-- | arch/powerpc/pthread_arch.h | 1 | ||||
-rw-r--r-- | arch/x32/pthread_arch.h | 2 |
2 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/pthread_arch.h b/arch/powerpc/pthread_arch.h index 2d1ee43c..4115ec8c 100644 --- a/arch/powerpc/pthread_arch.h +++ b/arch/powerpc/pthread_arch.h @@ -17,3 +17,4 @@ static inline struct pthread *__pthread_self() // GPRs. #define CANCEL_REG_IP 32 +#define CANARY canary_at_end diff --git a/arch/x32/pthread_arch.h b/arch/x32/pthread_arch.h index 23e10516..033bfd69 100644 --- a/arch/x32/pthread_arch.h +++ b/arch/x32/pthread_arch.h @@ -8,3 +8,5 @@ static inline struct pthread *__pthread_self() #define TP_ADJ(p) (p) #define CANCEL_REG_IP 32 + +#define CANARY canary2 |