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authorAlexey Dobriyan <adobriyan@gmail.com>2019-03-07 16:28:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-07 18:32:01 -0800
commitfaf1c3152032275370f35dc757501ae0c47ded53 (patch)
treee1475c6f6c72d43053927fb430894d0157a155e3 /fs
parentepoll: use rwlock in order to reduce ep_poll_callback() contention (diff)
downloadlinux-dev-faf1c3152032275370f35dc757501ae0c47ded53.tar.xz
linux-dev-faf1c3152032275370f35dc757501ae0c47ded53.zip
fs/binfmt_elf.c: don't be afraid of overflow
Number of ELF program headers is 16-bit by spec, so total size comfortably fits into "unsigned int". Space savings: 7 bytes! add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-7 (-7) Function old new delta load_elf_phdrs 137 130 -7 Link: http://lkml.kernel.org/r/20190204202715.GA27482@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/binfmt_elf.c9
1 files changed, 3 insertions, 6 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 54207327f98f..fd4b618c412e 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -418,8 +418,9 @@ static struct elf_phdr *load_elf_phdrs(struct elfhdr *elf_ex,
struct file *elf_file)
{
struct elf_phdr *elf_phdata = NULL;
- int retval, size, err = -1;
+ int retval, err = -1;
loff_t pos = elf_ex->e_phoff;
+ unsigned int size;
/*
* If the size of this structure has changed, then punt, since
@@ -429,13 +430,9 @@ static struct elf_phdr *load_elf_phdrs(struct elfhdr *elf_ex,
goto out;
/* Sanity check the number of program headers... */
- if (elf_ex->e_phnum < 1 ||
- elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
- goto out;
-
/* ...and their total size. */
size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
- if (size > ELF_MIN_ALIGN)
+ if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN)
goto out;
elf_phdata = kmalloc(size, GFP_KERNEL);