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elf: Fix failure handling in _dl_map_object_from_fd

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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).
This commit is contained in:
Szabolcs Nagy 2020-11-24 12:34:39 +00:00
parent 42de8ccdaf
commit 9ca7fe6033
1 changed files with 15 additions and 9 deletions
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24
elf/dl-load.c
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@ -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);