diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2018-01-29 04:49:00 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-31 14:55:57 +0300 |
| commit | 265d7657c9baf09d57eb386d0374e912e9649626 (patch) | |
| tree | 1f946e259824241ecee5a0137457a87dc3cc0435 /net | |
| parent | 4606077802f2c6ef7aff5185d9f7d99a50784ffd (diff) | |
| download | linux-265d7657c9baf09d57eb386d0374e912e9649626.tar.xz | |
bpf: fix 32-bit divide by zero
[ upstream commit 68fda450a7df51cff9e5a4d4a4d9d0d5f2589153 ]
due to some JITs doing if (src_reg == 0) check in 64-bit mode
for div/mod operations mask upper 32-bits of src register
before doing the check
Fixes: 622582786c9e ("net: filter: x86: internal BPF JIT")
Fixes: 7a12b5031c6b ("sparc64: Add eBPF JIT.")
Reported-by: syzbot+48340bb518e88849e2e3@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/filter.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 6e0d17bc8382..e8c89d2d2bc0 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -441,6 +441,10 @@ do_pass: convert_bpf_extensions(fp, &insn)) break; + if (fp->code == (BPF_ALU | BPF_DIV | BPF_X) || + fp->code == (BPF_ALU | BPF_MOD | BPF_X)) + *insn++ = BPF_MOV32_REG(BPF_REG_X, BPF_REG_X); + *insn = BPF_RAW_INSN(fp->code, BPF_REG_A, BPF_REG_X, 0, fp->k); break; |