In preparation to support PT_LOAD with large p_align values on
non-PT_INTERP ET_DYN executables (i.e. "static pie"), we'll need to use
the total_size details earlier. Move this separately now to make the
next patch more readable. As total_size and load_bias are currently
calculated separately, this has no behavioral impact.
Signed-off-by: Kees Cook <keesc...@chromium.org>
---
fs/binfmt_elf.c | 52 +++++++++++++++++++++++++------------------------
1 file changed, 27 insertions(+), 25 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 5397b552fbeb..56432e019d4e 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1061,7 +1061,34 @@ static int load_elf_binary(struct linux_binprm *bprm)
* Header for ET_DYN binaries to calculate the
* randomization (load_bias) for all the LOAD
* Program Headers.
+ */
+
+ /*
+ * Calculate the entire size of the ELF mapping
+ * (total_size), used for the initial mapping,
+ * due to load_addr_set which is set to true later
+ * once the initial mapping is performed.
+ *
+ * Note that this is only sensible when the LOAD
+ * segments are contiguous (or overlapping). If
+ * used for LOADs that are far apart, this would
+ * cause the holes between LOADs to be mapped,
+ * running the risk of having the mapping fail,
+ * as it would be larger than the ELF file itself.
*
+ * As a result, only ET_DYN does this, since
+ * some ET_EXEC (e.g. ia64) may have large virtual
+ * memory holes between LOADs.
+ *
+ */
+ total_size = total_mapping_size(elf_phdata,
+ elf_ex->e_phnum);
+ if (!total_size) {
+ retval = -EINVAL;
+ goto out_free_dentry;
+ }
+
+ /*
* There are effectively two types of ET_DYN
* binaries: programs (i.e. PIE: ET_DYN with INTERP)
* and loaders (ET_DYN without INTERP, since they
@@ -1102,31 +1129,6 @@ static int load_elf_binary(struct linux_binprm *bprm)
* is then page aligned.
*/
load_bias = ELF_PAGESTART(load_bias - vaddr);
-
- /*
- * Calculate the entire size of the ELF mapping
- * (total_size), used for the initial mapping,
- * due to load_addr_set which is set to true later
- * once the initial mapping is performed.
- *
- * Note that this is only sensible when the LOAD
- * segments are contiguous (or overlapping). If
- * used for LOADs that are far apart, this would
- * cause the holes between LOADs to be mapped,
- * running the risk of having the mapping fail,
- * as it would be larger than the ELF file itself.
- *
- * As a result, only ET_DYN does this, since
- * some ET_EXEC (e.g. ia64) may have large virtual
- * memory holes between LOADs.
- *
- */
- total_size = total_mapping_size(elf_phdata,
- elf_ex->e_phnum);
- if (!total_size) {
- retval = -EINVAL;
- goto out_free_dentry;
- }
}
error = elf_load(bprm->file, load_bias + vaddr, elf_ppnt,
--
2.34.1
