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| author |   Alexei Starovoitov <ast@kernel.org> | 2018-01-12 18:59:52 -0800 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2018-01-14 23:05:33 +0100 |
| commit | 68fda450a7df51cff9e5a4d4a4d9d0d5f2589153 (patch) | |
| tree | 555aa6473c3d960c0a95bd9c4843c8b48947cf1f /net/core/filter.c | |
| parent | bpf: fix divides by zero (diff) | |
| download | linux-dev-68fda450a7df51cff9e5a4d4a4d9d0d5f2589153.tar.xz linux-dev-68fda450a7df51cff9e5a4d4a4d9d0d5f2589153.zip | |
bpf: fix 32-bit divide by zero
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>
Diffstat (limited to 'net/core/filter.c')
| -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 d339ef170df6..1c0eb436671f 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -458,6 +458,10 @@ 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; |