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| author | Rich Felker <dalias@aerifal.cx> | 2014-08-22 14:05:10 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2014-08-22 14:05:10 -0400 |
| commit | a6293285e930dbdb0eff47e29b513ca22537b1a2 (patch) | |
| tree | 66a43238db0d04793fd682bf79f5d23745659b20 /src | |
| parent | 321f4fa9067185aa6bb47403dfba46e8cfe917d3 (diff) | |
| download | musl-a6293285e930dbdb0eff47e29b513ca22537b1a2.tar.gz musl-a6293285e930dbdb0eff47e29b513ca22537b1a2.tar.xz musl-a6293285e930dbdb0eff47e29b513ca22537b1a2.zip | |
fix use of uninitialized memory with application-provided thread stacks
the subsequent code in pthread_create and the code which copies TLS initialization images to the new thread's TLS space assume that the memory provided to them is zero-initialized, which is true when it's obtained by pthread_create using mmap. however, when the caller provides a stack using pthread_attr_setstack, pthread_create cannot make any assumptions about the contents. simply zero-filling the relevant memory in this case is the simplest and safest fix.
Diffstat (limited to 'src')
| -rw-r--r-- | src/thread/pthread_create.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c index c8c117b9..1601614a 100644 --- a/src/thread/pthread_create.c +++ b/src/thread/pthread_create.c @@ -3,6 +3,7 @@ #include "stdio_impl.h" #include "libc.h" #include <sys/mman.h> +#include <string.h> static void dummy_0() { @@ -175,6 +176,7 @@ int pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict attrp if (need < size/8 && need < 2048) { tsd = stack - __pthread_tsd_size; stack = tsd - libc.tls_size; + memset(stack, 0, need); } else { size = ROUND(need); guard = 0; |