Message ID | 20231002132404.249890-1-josimmon@redhat.com |
---|---|
State | New |
Headers | show |
Series | elf: dl-load: Get rid of alloca usage. | expand |
Ping. On Mon, Oct 02, 2023 at 09:24:01AM -0400, Joe Simmons-Talbott wrote: > Replace alloca usage with scratch_buffers. Change the sematics of > is_trusted_path_normalize to return 1, 0, or -1 on error. > --- > elf/dl-load.c | 72 ++++++++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 60 insertions(+), 12 deletions(-) > > diff --git a/elf/dl-load.c b/elf/dl-load.c > index 2923b1141d..c8e135b6e5 100644 > --- a/elf/dl-load.c > +++ b/elf/dl-load.c > @@ -21,6 +21,7 @@ > #include <errno.h> > #include <fcntl.h> > #include <libintl.h> > +#include <scratch_buffer.h> > #include <stdbool.h> > #include <stdlib.h> > #include <string.h> > @@ -124,14 +125,21 @@ static const size_t system_dirs_len[] = > }; > #define nsystem_dirs_len array_length (system_dirs_len) > > -static bool > +static int > is_trusted_path_normalize (const char *path, size_t len) > { > if (len == 0) > - return false; > + return 0; > + > + struct scratch_buffer sbuf; > + scratch_buffer_init (&sbuf); > + > + if (!scratch_buffer_set_array_size (&sbuf, 1, len + 2)) > + return -1; > > - char *npath = (char *) alloca (len + 2); > + char *npath = sbuf.data; > char *wnp = npath; > + > while (*path != '\0') > { > if (path[0] == '/') > @@ -172,12 +180,12 @@ is_trusted_path_normalize (const char *path, size_t len) > if (wnp - npath >= system_dirs_len[idx] > && memcmp (trun, npath, system_dirs_len[idx]) == 0) > /* Found it. */ > - return true; > + return 1; > > trun += system_dirs_len[idx] + 1; > } > > - return false; > + return 0; > } > > /* Given a substring starting at INPUT, just after the DST '$' start > @@ -363,7 +371,7 @@ _dl_dst_substitute (struct link_map *l, const char *input, char *result) > this way because it may be manipulated in some ways with hard > links. */ > if (__glibc_unlikely (check_for_trusted) > - && !is_trusted_path_normalize (result, wp - result)) > + && is_trusted_path_normalize (result, wp - result) != 1) > { > *result = '\0'; > return result; > @@ -951,6 +959,8 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > /* Initialize to keep the compiler happy. */ > const char *errstring = NULL; > int errval = 0; > + struct scratch_buffer sbuf; > + scratch_buffer_init (&sbuf); > > /* Get file information. To match the kernel behavior, do not fill > in this information for the executable in case of an explicit > @@ -982,6 +992,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > free ((void *) l->l_phdr); > free (l); > free (realname); > + scratch_buffer_free (&sbuf); > _dl_signal_error (errval, name, NULL, errstring); > } > > @@ -998,6 +1009,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > free (realname); > add_name_to_object (l, name); > > + scratch_buffer_free (&sbuf); > return l; > } > } > @@ -1029,6 +1041,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > /* Add the map for the mirrored object to the object list. */ > _dl_add_to_namespace_list (l, nsid); > > + scratch_buffer_free (&sbuf); > return l; > } > #endif > @@ -1039,6 +1052,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > loaded. So return now. */ > free (realname); > __close_nocancel (fd); > + scratch_buffer_free (&sbuf); > return NULL; > } > > @@ -1071,7 +1085,12 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > phdr = (void *) (fbp->buf + header->e_phoff); > else > { > - phdr = alloca (maplength); > + if (!scratch_buffer_set_array_size (&sbuf, 1, maplength)) > + { > + errstring = N_("cannot allocate memory"); > + goto lose_errno; > + } > + phdr = sbuf.data; > if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength, > header->e_phoff) != maplength) > { > @@ -1485,7 +1504,10 @@ cannot enable executable stack as shared object requires"); > > /* Skip auditing and debugger notification when called from 'sprof'. */ > if (mode & __RTLD_SPROF) > - return l; > + { > + scratch_buffer_free (&sbuf); > + return l; > + } > > /* Signal that we are going to add new objects. */ > struct r_debug *r = _dl_debug_update (nsid); > @@ -1515,6 +1537,7 @@ cannot enable executable stack as shared object requires"); > _dl_audit_objopen (l, nsid); > #endif > > + scratch_buffer_free (&sbuf); > return l; > } > > @@ -1598,6 +1621,8 @@ open_verify (const char *name, int fd, > /* Initialize it to make the compiler happy. */ > const char *errstring = NULL; > int errval = 0; > + struct scratch_buffer sbuf; > + scratch_buffer_init (&sbuf); > > #ifdef SHARED > /* Give the auditing libraries a chance. */ > @@ -1660,6 +1685,7 @@ open_verify (const char *name, int fd, > name = strdupa (realname); > free (realname); > } > + scratch_buffer_free (&sbuf); > __close_nocancel (fd); > _dl_signal_error (errval, name, NULL, errstring); > } > @@ -1696,6 +1722,7 @@ open_verify (const char *name, int fd, > 32-bit and 64-bit binaries can be run this might > happen. */ > *found_other_class = true; > + scratch_buffer_free (&sbuf); > __close_nocancel (fd); > __set_errno (ENOENT); > return -1; > @@ -1734,6 +1761,7 @@ open_verify (const char *name, int fd, > } > if (! __glibc_likely (elf_machine_matches_host (ehdr))) > { > + scratch_buffer_free (&sbuf); > __close_nocancel (fd); > __set_errno (ENOENT); > return -1; > @@ -1755,7 +1783,14 @@ open_verify (const char *name, int fd, > phdr = (void *) (fbp->buf + ehdr->e_phoff); > else > { > - phdr = alloca (maplength); > + if (!scratch_buffer_set_array_size (&sbuf, 1, maplength)) > + { > + errval = errno; > + errstring = N_("cannot allocate memory"); > + goto lose; > + } > + phdr = sbuf.data; > + > if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength, > ehdr->e_phoff) != maplength) > { > @@ -1769,6 +1804,7 @@ open_verify (const char *name, int fd, > (phdr, ehdr->e_phnum, fbp->buf, fbp->len, > loader, fd))) > { > + scratch_buffer_free (&sbuf); > __close_nocancel (fd); > __set_errno (ENOENT); > return -1; > @@ -1776,6 +1812,7 @@ open_verify (const char *name, int fd, > > } > > + scratch_buffer_free (&sbuf); > return fd; > } > > @@ -1796,13 +1833,18 @@ open_path (const char *name, size_t namelen, int mode, > int fd = -1; > const char *current_what = NULL; > int any = 0; > + struct scratch_buffer sbuf; > + scratch_buffer_init (&sbuf); > > if (__glibc_unlikely (dirs == NULL)) > /* We're called before _dl_init_paths when loading the main executable > given on the command line when rtld is run directly. */ > return -1; > > - buf = alloca (max_dirnamelen + max_capstrlen + namelen); > + if (!scratch_buffer_set_array_size (&sbuf, 1, > + max_dirnamelen + max_capstrlen + namelen)) > + return -1; > + buf = sbuf.data; > do > { > struct r_search_path_elem *this_dir = *dirs; > @@ -1901,6 +1943,7 @@ open_path (const char *name, size_t namelen, int mode, > if (*realname != NULL) > { > memcpy (*realname, buf, buflen); > + scratch_buffer_free (&sbuf); > return fd; > } > else > @@ -1908,12 +1951,16 @@ open_path (const char *name, size_t namelen, int mode, > /* No memory for the name, we certainly won't be able > to load and link it. */ > __close_nocancel (fd); > + scratch_buffer_free (&sbuf); > return -1; > } > } > if (here_any && (err = errno) != ENOENT && err != EACCES) > - /* The file exists and is readable, but something went wrong. */ > - return -1; > + { > + /* The file exists and is readable, but something went wrong. */ > + scratch_buffer_free (&sbuf); > + return -1; > + } > > /* Remember whether we found anything. */ > any |= here_any; > @@ -1934,6 +1981,7 @@ open_path (const char *name, size_t namelen, int mode, > sps->dirs = (void *) -1; > } > > + scratch_buffer_free (&sbuf); > return -1; > } > > -- > 2.39.2 >
On 02/10/23 10:24, Joe Simmons-Talbott wrote: > Replace alloca usage with scratch_buffers. Change the sematics of > is_trusted_path_normalize to return 1, 0, or -1 on error. > --- > elf/dl-load.c | 72 ++++++++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 60 insertions(+), 12 deletions(-) > > diff --git a/elf/dl-load.c b/elf/dl-load.c > index 2923b1141d..c8e135b6e5 100644 > --- a/elf/dl-load.c > +++ b/elf/dl-load.c > @@ -21,6 +21,7 @@ > #include <errno.h> > #include <fcntl.h> > #include <libintl.h> > +#include <scratch_buffer.h> > #include <stdbool.h> > #include <stdlib.h> > #include <string.h> > @@ -124,14 +125,21 @@ static const size_t system_dirs_len[] = > }; > #define nsystem_dirs_len array_length (system_dirs_len) > > -static bool > +static int The main problem is _dl_dst_substitute, which calls is_trusted_path_normalize, is not suppose to fail. The expand_dynamic_string_token does handle null, but fillin_rpath will just ignore the entry. I think it should _dl_signal_error (ENOMEM, ...). Same for expand_dst macro, which does not expect to _dl_dst_substitute fail with memory allocation. So I think it would be better to split the patch to first only remove the alloca from is_trusted_path_normalize, add memory allocation checks on _dl_dst_substitute to return NULL if is_trusted_path_normalize fails to allocate memory, and add NULL checks for _dl_dst_substitute callers as well. > is_trusted_path_normalize (const char *path, size_t len) > { > if (len == 0) > - return false; > + return 0; > + > + struct scratch_buffer sbuf; > + scratch_buffer_init (&sbuf); > + > + if (!scratch_buffer_set_array_size (&sbuf, 1, len + 2)) > + return -1; > > - char *npath = (char *) alloca (len + 2); > + char *npath = sbuf.data; > char *wnp = npath; > + > while (*path != '\0') > { > if (path[0] == '/') > @@ -172,12 +180,12 @@ is_trusted_path_normalize (const char *path, size_t len) > if (wnp - npath >= system_dirs_len[idx] > && memcmp (trun, npath, system_dirs_len[idx]) == 0) > /* Found it. */ > - return true; > + return 1; > > trun += system_dirs_len[idx] + 1; > } > > - return false; > + return 0; It misses the scratch_buffer_free for sbuf. > } > > /* Given a substring starting at INPUT, just after the DST '$' start > @@ -363,7 +371,7 @@ _dl_dst_substitute (struct link_map *l, const char *input, char *result) > this way because it may be manipulated in some ways with hard > links. */ > if (__glibc_unlikely (check_for_trusted) > - && !is_trusted_path_normalize (result, wp - result)) > + && is_trusted_path_normalize (result, wp - result) != 1) > { > *result = '\0'; > return result; > @@ -951,6 +959,8 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > /* Initialize to keep the compiler happy. */ > const char *errstring = NULL; > int errval = 0; > + struct scratch_buffer sbuf; > + scratch_buffer_init (&sbuf); > > /* Get file information. To match the kernel behavior, do not fill > in this information for the executable in case of an explicit > @@ -982,6 +992,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > free ((void *) l->l_phdr); > free (l); > free (realname); > + scratch_buffer_free (&sbuf); > _dl_signal_error (errval, name, NULL, errstring); > } > > @@ -998,6 +1009,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > free (realname); > add_name_to_object (l, name); > > + scratch_buffer_free (&sbuf); > return l; > } > } > @@ -1029,6 +1041,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > /* Add the map for the mirrored object to the object list. */ > _dl_add_to_namespace_list (l, nsid); > > + scratch_buffer_free (&sbuf); > return l; > } > #endif > @@ -1039,6 +1052,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > loaded. So return now. */ > free (realname); > __close_nocancel (fd); > + scratch_buffer_free (&sbuf); > return NULL; > } > > @@ -1071,7 +1085,12 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, > phdr = (void *) (fbp->buf + header->e_phoff); > else > { > - phdr = alloca (maplength); > + if (!scratch_buffer_set_array_size (&sbuf, 1, maplength)) > + { > + errstring = N_("cannot allocate memory"); > + goto lose_errno; > + } > + phdr = sbuf.data; > if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength, > header->e_phoff) != maplength) > { > @@ -1485,7 +1504,10 @@ cannot enable executable stack as shared object requires"); > > /* Skip auditing and debugger notification when called from 'sprof'. */ > if (mode & __RTLD_SPROF) > - return l; > + { > + scratch_buffer_free (&sbuf); > + return l; > + } > > /* Signal that we are going to add new objects. */ > struct r_debug *r = _dl_debug_update (nsid); > @@ -1515,6 +1537,7 @@ cannot enable executable stack as shared object requires"); > _dl_audit_objopen (l, nsid); > #endif > > + scratch_buffer_free (&sbuf); > return l; > } > > @@ -1598,6 +1621,8 @@ open_verify (const char *name, int fd, > /* Initialize it to make the compiler happy. */ > const char *errstring = NULL; > int errval = 0; > + struct scratch_buffer sbuf; > + scratch_buffer_init (&sbuf); > > #ifdef SHARED > /* Give the auditing libraries a chance. */ > @@ -1660,6 +1685,7 @@ open_verify (const char *name, int fd, > name = strdupa (realname); > free (realname); > } > + scratch_buffer_free (&sbuf); > __close_nocancel (fd); > _dl_signal_error (errval, name, NULL, errstring); > } > @@ -1696,6 +1722,7 @@ open_verify (const char *name, int fd, > 32-bit and 64-bit binaries can be run this might > happen. */ > *found_other_class = true; > + scratch_buffer_free (&sbuf); > __close_nocancel (fd); > __set_errno (ENOENT); > return -1; > @@ -1734,6 +1761,7 @@ open_verify (const char *name, int fd, > } > if (! __glibc_likely (elf_machine_matches_host (ehdr))) > { > + scratch_buffer_free (&sbuf); > __close_nocancel (fd); > __set_errno (ENOENT); > return -1; > @@ -1755,7 +1783,14 @@ open_verify (const char *name, int fd, > phdr = (void *) (fbp->buf + ehdr->e_phoff); > else > { > - phdr = alloca (maplength); > + if (!scratch_buffer_set_array_size (&sbuf, 1, maplength)) > + { > + errval = errno; > + errstring = N_("cannot allocate memory"); > + goto lose; > + } > + phdr = sbuf.data; > + > if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength, > ehdr->e_phoff) != maplength) > { > @@ -1769,6 +1804,7 @@ open_verify (const char *name, int fd, > (phdr, ehdr->e_phnum, fbp->buf, fbp->len, > loader, fd))) > { > + scratch_buffer_free (&sbuf); > __close_nocancel (fd); > __set_errno (ENOENT); > return -1; > @@ -1776,6 +1812,7 @@ open_verify (const char *name, int fd, > > } > > + scratch_buffer_free (&sbuf); > return fd; > } > > @@ -1796,13 +1833,18 @@ open_path (const char *name, size_t namelen, int mode, > int fd = -1; > const char *current_what = NULL; > int any = 0; > + struct scratch_buffer sbuf; > + scratch_buffer_init (&sbuf); > > if (__glibc_unlikely (dirs == NULL)) > /* We're called before _dl_init_paths when loading the main executable > given on the command line when rtld is run directly. */ > return -1; > > - buf = alloca (max_dirnamelen + max_capstrlen + namelen); > + if (!scratch_buffer_set_array_size (&sbuf, 1, > + max_dirnamelen + max_capstrlen + namelen)) > + return -1; > + buf = sbuf.data; > do > { > struct r_search_path_elem *this_dir = *dirs; > @@ -1901,6 +1943,7 @@ open_path (const char *name, size_t namelen, int mode, > if (*realname != NULL) > { > memcpy (*realname, buf, buflen); > + scratch_buffer_free (&sbuf); > return fd; > } > else > @@ -1908,12 +1951,16 @@ open_path (const char *name, size_t namelen, int mode, > /* No memory for the name, we certainly won't be able > to load and link it. */ > __close_nocancel (fd); > + scratch_buffer_free (&sbuf); > return -1; > } > } > if (here_any && (err = errno) != ENOENT && err != EACCES) > - /* The file exists and is readable, but something went wrong. */ > - return -1; > + { > + /* The file exists and is readable, but something went wrong. */ > + scratch_buffer_free (&sbuf); > + return -1; > + } > > /* Remember whether we found anything. */ > any |= here_any; > @@ -1934,6 +1981,7 @@ open_path (const char *name, size_t namelen, int mode, > sps->dirs = (void *) -1; > } > > + scratch_buffer_free (&sbuf); > return -1; > } >
On Tue, Oct 17, 2023 at 02:50:41PM -0300, Adhemerval Zanella Netto wrote: > > > On 02/10/23 10:24, Joe Simmons-Talbott wrote: > > Replace alloca usage with scratch_buffers. Change the sematics of > > is_trusted_path_normalize to return 1, 0, or -1 on error. > > --- > > elf/dl-load.c | 72 ++++++++++++++++++++++++++++++++++++++++++--------- > > 1 file changed, 60 insertions(+), 12 deletions(-) > > > > diff --git a/elf/dl-load.c b/elf/dl-load.c > > index 2923b1141d..c8e135b6e5 100644 > > --- a/elf/dl-load.c > > +++ b/elf/dl-load.c > > @@ -21,6 +21,7 @@ > > #include <errno.h> > > #include <fcntl.h> > > #include <libintl.h> > > +#include <scratch_buffer.h> > > #include <stdbool.h> > > #include <stdlib.h> > > #include <string.h> > > @@ -124,14 +125,21 @@ static const size_t system_dirs_len[] = > > }; > > #define nsystem_dirs_len array_length (system_dirs_len) > > > > -static bool > > +static int > > The main problem is _dl_dst_substitute, which calls is_trusted_path_normalize, > is not suppose to fail. The expand_dynamic_string_token does handle null, > but fillin_rpath will just ignore the entry. I think it should > _dl_signal_error (ENOMEM, ...). > > Same for expand_dst macro, which does not expect to _dl_dst_substitute fail > with memory allocation. > > So I think it would be better to split the patch to first only remove the > alloca from is_trusted_path_normalize, add memory allocation checks on > _dl_dst_substitute to return NULL if is_trusted_path_normalize fails to > allocate memory, and add NULL checks for _dl_dst_substitute callers as well. I've posted a v2 which hopefully does as you've suggested. I also added the scratch_buffer_free that was overlooked. Thanks for your review. Thanks, Joe
diff --git a/elf/dl-load.c b/elf/dl-load.c index 2923b1141d..c8e135b6e5 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -21,6 +21,7 @@ #include <errno.h> #include <fcntl.h> #include <libintl.h> +#include <scratch_buffer.h> #include <stdbool.h> #include <stdlib.h> #include <string.h> @@ -124,14 +125,21 @@ static const size_t system_dirs_len[] = }; #define nsystem_dirs_len array_length (system_dirs_len) -static bool +static int is_trusted_path_normalize (const char *path, size_t len) { if (len == 0) - return false; + return 0; + + struct scratch_buffer sbuf; + scratch_buffer_init (&sbuf); + + if (!scratch_buffer_set_array_size (&sbuf, 1, len + 2)) + return -1; - char *npath = (char *) alloca (len + 2); + char *npath = sbuf.data; char *wnp = npath; + while (*path != '\0') { if (path[0] == '/') @@ -172,12 +180,12 @@ is_trusted_path_normalize (const char *path, size_t len) if (wnp - npath >= system_dirs_len[idx] && memcmp (trun, npath, system_dirs_len[idx]) == 0) /* Found it. */ - return true; + return 1; trun += system_dirs_len[idx] + 1; } - return false; + return 0; } /* Given a substring starting at INPUT, just after the DST '$' start @@ -363,7 +371,7 @@ _dl_dst_substitute (struct link_map *l, const char *input, char *result) this way because it may be manipulated in some ways with hard links. */ if (__glibc_unlikely (check_for_trusted) - && !is_trusted_path_normalize (result, wp - result)) + && is_trusted_path_normalize (result, wp - result) != 1) { *result = '\0'; return result; @@ -951,6 +959,8 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, /* Initialize to keep the compiler happy. */ const char *errstring = NULL; int errval = 0; + struct scratch_buffer sbuf; + scratch_buffer_init (&sbuf); /* Get file information. To match the kernel behavior, do not fill in this information for the executable in case of an explicit @@ -982,6 +992,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, free ((void *) l->l_phdr); free (l); free (realname); + scratch_buffer_free (&sbuf); _dl_signal_error (errval, name, NULL, errstring); } @@ -998,6 +1009,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, free (realname); add_name_to_object (l, name); + scratch_buffer_free (&sbuf); return l; } } @@ -1029,6 +1041,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, /* Add the map for the mirrored object to the object list. */ _dl_add_to_namespace_list (l, nsid); + scratch_buffer_free (&sbuf); return l; } #endif @@ -1039,6 +1052,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, loaded. So return now. */ free (realname); __close_nocancel (fd); + scratch_buffer_free (&sbuf); return NULL; } @@ -1071,7 +1085,12 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, phdr = (void *) (fbp->buf + header->e_phoff); else { - phdr = alloca (maplength); + if (!scratch_buffer_set_array_size (&sbuf, 1, maplength)) + { + errstring = N_("cannot allocate memory"); + goto lose_errno; + } + phdr = sbuf.data; if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength, header->e_phoff) != maplength) { @@ -1485,7 +1504,10 @@ cannot enable executable stack as shared object requires"); /* Skip auditing and debugger notification when called from 'sprof'. */ if (mode & __RTLD_SPROF) - return l; + { + scratch_buffer_free (&sbuf); + return l; + } /* Signal that we are going to add new objects. */ struct r_debug *r = _dl_debug_update (nsid); @@ -1515,6 +1537,7 @@ cannot enable executable stack as shared object requires"); _dl_audit_objopen (l, nsid); #endif + scratch_buffer_free (&sbuf); return l; } @@ -1598,6 +1621,8 @@ open_verify (const char *name, int fd, /* Initialize it to make the compiler happy. */ const char *errstring = NULL; int errval = 0; + struct scratch_buffer sbuf; + scratch_buffer_init (&sbuf); #ifdef SHARED /* Give the auditing libraries a chance. */ @@ -1660,6 +1685,7 @@ open_verify (const char *name, int fd, name = strdupa (realname); free (realname); } + scratch_buffer_free (&sbuf); __close_nocancel (fd); _dl_signal_error (errval, name, NULL, errstring); } @@ -1696,6 +1722,7 @@ open_verify (const char *name, int fd, 32-bit and 64-bit binaries can be run this might happen. */ *found_other_class = true; + scratch_buffer_free (&sbuf); __close_nocancel (fd); __set_errno (ENOENT); return -1; @@ -1734,6 +1761,7 @@ open_verify (const char *name, int fd, } if (! __glibc_likely (elf_machine_matches_host (ehdr))) { + scratch_buffer_free (&sbuf); __close_nocancel (fd); __set_errno (ENOENT); return -1; @@ -1755,7 +1783,14 @@ open_verify (const char *name, int fd, phdr = (void *) (fbp->buf + ehdr->e_phoff); else { - phdr = alloca (maplength); + if (!scratch_buffer_set_array_size (&sbuf, 1, maplength)) + { + errval = errno; + errstring = N_("cannot allocate memory"); + goto lose; + } + phdr = sbuf.data; + if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength, ehdr->e_phoff) != maplength) { @@ -1769,6 +1804,7 @@ open_verify (const char *name, int fd, (phdr, ehdr->e_phnum, fbp->buf, fbp->len, loader, fd))) { + scratch_buffer_free (&sbuf); __close_nocancel (fd); __set_errno (ENOENT); return -1; @@ -1776,6 +1812,7 @@ open_verify (const char *name, int fd, } + scratch_buffer_free (&sbuf); return fd; } @@ -1796,13 +1833,18 @@ open_path (const char *name, size_t namelen, int mode, int fd = -1; const char *current_what = NULL; int any = 0; + struct scratch_buffer sbuf; + scratch_buffer_init (&sbuf); if (__glibc_unlikely (dirs == NULL)) /* We're called before _dl_init_paths when loading the main executable given on the command line when rtld is run directly. */ return -1; - buf = alloca (max_dirnamelen + max_capstrlen + namelen); + if (!scratch_buffer_set_array_size (&sbuf, 1, + max_dirnamelen + max_capstrlen + namelen)) + return -1; + buf = sbuf.data; do { struct r_search_path_elem *this_dir = *dirs; @@ -1901,6 +1943,7 @@ open_path (const char *name, size_t namelen, int mode, if (*realname != NULL) { memcpy (*realname, buf, buflen); + scratch_buffer_free (&sbuf); return fd; } else @@ -1908,12 +1951,16 @@ open_path (const char *name, size_t namelen, int mode, /* No memory for the name, we certainly won't be able to load and link it. */ __close_nocancel (fd); + scratch_buffer_free (&sbuf); return -1; } } if (here_any && (err = errno) != ENOENT && err != EACCES) - /* The file exists and is readable, but something went wrong. */ - return -1; + { + /* The file exists and is readable, but something went wrong. */ + scratch_buffer_free (&sbuf); + return -1; + } /* Remember whether we found anything. */ any |= here_any; @@ -1934,6 +1981,7 @@ open_path (const char *name, size_t namelen, int mode, sps->dirs = (void *) -1; } + scratch_buffer_free (&sbuf); return -1; }