Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2025-01-09 07:23:14 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

bpf: bpf_prog_pack: Set proper size before freeing ro_header

Browse Source 
bpf_prog_pack_free() uses header->size to decide whether the header
should be freed with module_memfree() or the bpf_prog_pack logic.
However, in kvmalloc() failure path of bpf_jit_binary_pack_alloc(),
header->size is not set yet. As a result, bpf_prog_pack_free() may treat
a slice of a pack as a standalone kvmalloc'd header and call
module_memfree() on the whole pack. This in turn causes use-after-free by
other users of the pack.

Fix this by setting ro_header->size before freeing ro_header.

Fixes: 33c9805860 ("bpf: Introduce bpf_jit_binary_pack_[alloc|finalize|free]")
Reported-by: syzbot+2f649ec6d2eea1495a8f@syzkaller.appspotmail.com
Reported-by: syzbot+ecb1e7e51c52f68f7481@syzkaller.appspotmail.com
Reported-by: syzbot+87f65c75f4a72db05445@syzkaller.appspotmail.com
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220217183001.1876034-1-song@kernel.org
This commit is contained in:
Song Liu 2022-02-17 10:30:01 -08:00 committed by Alexei Starovoitov
parent b75dacaac4
commit d24d2a2b0a
1 changed files with 1 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
kernel/bpf/core.c
View File

@ -1069,6 +1069,7 @@ bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
*rw_header = kvmalloc(size, GFP_KERNEL);
if (!*rw_header) {
bpf_arch_text_copy(&ro_header->size, &size, sizeof(size));
bpf_prog_pack_free(ro_header);
bpf_jit_uncharge_modmem(size);
return NULL;