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| author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2022-10-21 12:35:33 +0100 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2022-10-26 15:32:01 +0100 |
| commit | 44283b4f2ff4dd8976209b6438e4279a0f3f07d5 (patch) | |
| tree | ad7027bcfedf79778c411de62ab1858df74dd823 | |
| parent | 418ede06d733e2388decf9a2b9f60674463d14d1 (diff) | |
| download | glibc-44283b4f2ff4dd8976209b6438e4279a0f3f07d5.tar.gz glibc-44283b4f2ff4dd8976209b6438e4279a0f3f07d5.tar.xz glibc-44283b4f2ff4dd8976209b6438e4279a0f3f07d5.zip | |
cheri: malloc: Ensure the mappings have RW permission
The arena allocator incrementally applies RW mprotect to a PROT_NONE mapping. Use PROT_MAX to ensure the pointers derived from the original mapping have RW capability permission.
| -rw-r--r-- | malloc/malloc.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/malloc/malloc.c b/malloc/malloc.c index cc222eaba2..392116a5ac 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -1284,8 +1284,16 @@ static mchunkptr mremap_chunk(mchunkptr p, size_t new_size); # define MAP_NORESERVE 0 #endif +/* Allow RW mprotect later, on CHERI this means RW capability permission. */ +#ifdef PROT_MAX +# define PROT_MAX_RW PROT_MAX (PROT_READ | PROT_WRITE) +#else +# define PROT_MAX_RW 0 +#endif + #define MMAP(addr, size, prot, flags) \ - __mmap((addr), (size), (prot), (flags)|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0) + __mmap((addr), (size), (prot)|PROT_MAX_RW, \ + (flags)|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0) /* |