6.1-stable review patch. If anyone has any objections, please let me know.
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From: Kees Cook kees@kernel.org
[ Upstream commit 2d4cf7b190bbfadd4986bf5c34da17c1a88adf8e ]
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.
Link: https://lore.kernel.org/r/20240508173149.677910-2-keescook@chromium.org Signed-off-by: Kees Cook kees@kernel.org Stable-dep-of: 11854fe263eb ("binfmt_elf: Move brk for static PIE even if ASLR disabled") Signed-off-by: Sasha Levin sashal@kernel.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 ff796910265da..26abe256e91fb 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1093,7 +1093,34 @@ 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 @@ -1134,31 +1161,6 @@ 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,