diff options
| author | Song Liu <song@kernel.org> | 2022-02-17 10:30:01 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-02-17 13:15:36 -0800 |
| commit | d24d2a2b0a81dd5e9bb99aeb4559ec9734e1416f (patch) | |
| tree | a5995c6791568b5220f927ffd228cf89c35087c9 /kernel | |
| parent | b75dacaac4650478ed5a9d33975b91b99016daff (diff) | |
bpf: bpf_prog_pack: Set proper size before freeing ro_header
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: 33c9805860e5 ("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
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/core.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 44623c9b5bb1..ebb0193d07f0 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -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; |