From e1d2c8b69ad81ea103b1e87809eba51931e16874 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Tue, 29 Apr 2008 00:59:34 -0700
Subject: [PATCH] fdpic: check that the size returned by kernel_read() is what
we asked for
Check that the size of the read returned by kernel_read() is what we asked
for. If it isn't, then reject the binary as being a badly formatted.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/binfmt_elf_fdpic.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 32649f2a16544..ddd35d8733914 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -136,8 +136,8 @@ static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
retval = kernel_read(file, params->hdr.e_phoff,
(char *) params->phdrs, size);
- if (retval < 0)
- return retval;
+ if (unlikely(retval != size))
+ return retval < 0 ? retval : -ENOEXEC;
/* determine stack size for this binary */
phdr = params->phdrs;
@@ -218,8 +218,11 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
phdr->p_offset,
interpreter_name,
phdr->p_filesz);
- if (retval < 0)
+ if (unlikely(retval != phdr->p_filesz)) {
+ if (retval >= 0)
+ retval = -ENOEXEC;
goto error;
+ }
retval = -ENOENT;
if (interpreter_name[phdr->p_filesz - 1] != '\0')
@@ -245,8 +248,11 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
retval = kernel_read(interpreter, 0, bprm->buf,
BINPRM_BUF_SIZE);
- if (retval < 0)
+ if (unlikely(retval != BINPRM_BUF_SIZE)) {
+ if (retval >= 0)
+ retval = -ENOEXEC;
goto error;
+ }
interp_params.hdr = *((struct elfhdr *) bprm->buf);
break;
--
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