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author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-11-24 12:34:39 +0000 |
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committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-11-25 15:25:13 +0000 |
commit | 8ebf571196dd499c61983dbf53c94c68ebd458cc (patch) | |
tree | 8a04b7e9d0155107f628f5a2f6a708d8fde87610 | |
parent | f6788964bf6412da6fcdd3be4f67eb0417e558a6 (diff) | |
download | glibc-8ebf571196dd499c61983dbf53c94c68ebd458cc.tar.gz glibc-8ebf571196dd499c61983dbf53c94c68ebd458cc.tar.xz glibc-8ebf571196dd499c61983dbf53c94c68ebd458cc.zip |
elf: Fix failure handling in _dl_map_object_from_fd
There are many failure paths that call lose to do local cleanups in _dl_map_object_from_fd, but it did not clean everything. Handle l_phdr, l_libname and mapped segments in the common failure handling code. There are various bits that may not be cleaned properly on failure (e.g. executable stack, tlsid, incomplete dl_map_segments).
-rw-r--r-- | elf/dl-load.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/elf/dl-load.c b/elf/dl-load.c index 21e55deb19..9c71b7562c 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -914,8 +914,15 @@ lose (int code, int fd, const char *name, char *realname, struct link_map *l, /* The file might already be closed. */ if (fd != -1) (void) __close_nocancel (fd); + if (l != NULL && l->l_map_start != 0) + _dl_unmap_segments (l); if (l != NULL && l->l_origin != (char *) -1l) free ((char *) l->l_origin); + if (l != NULL && !l->l_libname->dont_free) + free (l->l_libname); + if (l != NULL && l->l_phdr_allocated) + free ((void *) l->l_phdr); + free (l); free (realname); @@ -1256,7 +1263,11 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds, maplength, has_holes, loader); if (__glibc_unlikely (errstring != NULL)) - goto call_lose; + { + /* Mappings can be in an inconsistent state: avoid unmap. */ + l->l_map_start = l->l_map_end = 0; + goto call_lose; + } /* Process program headers again after load segments are mapped in case processing requires accessing those segments. Scan program @@ -1294,14 +1305,6 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, || (__glibc_unlikely (l->l_flags_1 & DF_1_PIE) && __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0))) { - /* We are not supposed to load this object. Free all resources. */ - _dl_unmap_segments (l); - - if (!l->l_libname->dont_free) - free (l->l_libname); - - if (l->l_phdr_allocated) - free ((void *) l->l_phdr); if (l->l_flags_1 & DF_1_PIE) errstring @@ -1392,6 +1395,9 @@ cannot enable executable stack as shared object requires"); /* Signal that we closed the file. */ fd = -1; + /* Failures before this point are handled locally via lose. + No more failures are allowed in this function until return. */ + /* If this is ET_EXEC, we should have loaded it as lt_executable. */ assert (type != ET_EXEC || l->l_type == lt_executable); |