Merge tag 'binfmt_elf-v5.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull binfmt_elf fix from Kees Cook:
 "This addresses a regression[1] under ia64 where some ET_EXEC binaries
  were not loading"

Link: https://linux-regtracking.leemhuis.info/regzbot/regression/a3edd529-c42d-3b09-135c-7e98a15b150f@leemhuis.info/ [1]

- Fix ia64 ET_EXEC loading

* tag 'binfmt_elf-v5.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  binfmt_elf: Avoid total_mapping_size for ET_EXEC

1 files changed, 18 insertions, 7 deletions

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 9e11e6f13e83..d61543fbd652 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1135,14 +1135,25 @@ out_free_interp:
 			 * is then page aligned.
 			 */
 			load_bias = ELF_PAGESTART(load_bias - vaddr);
-		}
 
-		/*
-		 * Calculate the entire size of the ELF mapping (total_size).
-		 * (Note that load_addr_set is set to true later once the
-		 * initial mapping is performed.)
-		 */
-		if (!load_addr_set) {
+			/*
+			 * 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) {