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| author | Rich Felker <dalias@aerifal.cx> | 2018-04-19 22:19:29 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2018-04-19 22:22:11 -0400 |
| commit | b4b1e10364c8737a632be61582e05a8d3acf5690 (patch) | |
| tree | 68c07893e646a5e94c47afb7f8b01317c143968b /ldso | |
| parent | 72141795d4edd17f88da192447395a48444afa10 (diff) | |
| download | musl-b4b1e10364c8737a632be61582e05a8d3acf5690.tar.gz musl-b4b1e10364c8737a632be61582e05a8d3acf5690.tar.xz musl-b4b1e10364c8737a632be61582e05a8d3acf5690.zip | |
reintroduce hardening against partially-replaced allocator
commit 618b18c78e33acfe54a4434e91aa57b8e171df89 removed the previous detection and hardening since it was incorrect. commit 72141795d4edd17f88da192447395a48444afa10 already handled all that remained for hardening the static-linked case. in the dynamic-linked case, have the dynamic linker check whether malloc was replaced and make that information available. with these changes, the properties documented in commit c9f415d7ea2dace5bf77f6518b6afc36bb7a5732 are restored: if calloc is not provided, it will behave as malloc+memset, and any of the memalign-family functions not provided will fail with ENOMEM.
Diffstat (limited to 'ldso')
| -rw-r--r-- | ldso/dynlink.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/ldso/dynlink.c b/ldso/dynlink.c index 63e7b81f..cea5f452 100644 --- a/ldso/dynlink.c +++ b/ldso/dynlink.c @@ -134,6 +134,9 @@ static struct dso *const nodeps_dummy; struct debug *_dl_debug_addr = &debug; __attribute__((__visibility__("hidden"))) +extern int __malloc_replaced; + +__attribute__((__visibility__("hidden"))) void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0; __attribute__((__visibility__("hidden"))) @@ -1691,6 +1694,12 @@ _Noreturn void __dls3(size_t *sp) if (ldso_fail) _exit(127); if (ldd_mode) _exit(0); + /* Determine if malloc was interposed by a replacement implementation + * so that calloc and the memalign family can harden against the + * possibility of incomplete replacement. */ + if (find_sym(head, "malloc", 1).dso != &ldso) + __malloc_replaced = 1; + /* Switch to runtime mode: any further failures in the dynamic * linker are a reportable failure rather than a fatal startup * error. */ |