diff options
| author | Alexey Dobriyan <adobriyan@gmail.com> | 2022-05-04 12:54:20 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-12 16:35:09 +0200 |
| commit | 09cb6663618a74fe5572a4931ecbf098832e79ec (patch) | |
| tree | c77b4a09209814f4b50525c7e371bb085b4463a8 /kernel | |
| parent | e9f331bb5d433c9be52c4e3d9d4e2e41ef4d8493 (diff) | |
module: fix [e_shstrndx].sh_size=0 OOB access
[ Upstream commit 391e982bfa632b8315235d8be9c0a81374c6a19c ]
It is trivial to craft a module to trigger OOB access in this line:
if (info->secstrings[strhdr->sh_size - 1] != '\0') {
BUG: unable to handle page fault for address: ffffc90000aa0fff
PGD 100000067 P4D 100000067 PUD 100066067 PMD 10436f067 PTE 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 7 PID: 1215 Comm: insmod Not tainted 5.18.0-rc5-00007-g9bf578647087-dirty #10
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014
RIP: 0010:load_module+0x19b/0x2391
Fixes: ec2a29593c83 ("module: harden ELF info handling")
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
[rebased patch onto modules-next]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/module.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c index 256b3c80a771..ef79f4dbda87 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3029,6 +3029,10 @@ static int elf_validity_check(struct load_info *info) * strings in the section safe. */ info->secstrings = (void *)info->hdr + strhdr->sh_offset; + if (strhdr->sh_size == 0) { + pr_err("empty section name table\n"); + goto no_exec; + } if (info->secstrings[strhdr->sh_size - 1] != '\0') { pr_err("ELF Spec violation: section name table isn't null terminated\n"); goto no_exec; |