diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0100-bpf-fix-divides-by-zero.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0100-bpf-fix-divides-by-zero.patch | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0100-bpf-fix-divides-by-zero.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0100-bpf-fix-divides-by-zero.patch new file mode 100644 index 00000000..250d2bdb --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0100-bpf-fix-divides-by-zero.patch @@ -0,0 +1,46 @@ +From 9a13af743afd41c5fb1e0698b7638e76eaab9dcc Mon Sep 17 00:00:00 2001 +From: Eric Dumazet <edumazet@google.com> +Date: Mon, 29 Jan 2018 02:48:59 +0100 +Subject: [PATCH 100/102] bpf: fix divides by zero + +[ upstream commit c366287ebd698ef5e3de300d90cd62ee9ee7373e ] + +Divides by zero are not nice, lets avoid them if possible. + +Also do_div() seems not needed when dealing with 32bit operands, +but this seems a minor detail. + +Fixes: bd4cf0ed331a ("net: filter: rework/optimize internal BPF interpreter's instruction set") +Signed-off-by: Eric Dumazet <edumazet@google.com> +Reported-by: syzbot <syzkaller@googlegroups.com> +Signed-off-by: Alexei Starovoitov <ast@kernel.org> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + kernel/bpf/core.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c +index 64c4b13..879ca84 100644 +--- a/kernel/bpf/core.c ++++ b/kernel/bpf/core.c +@@ -642,7 +642,7 @@ static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) + DST = tmp; + CONT; + ALU_MOD_X: +- if (unlikely(SRC == 0)) ++ if (unlikely((u32)SRC == 0)) + return 0; + tmp = (u32) DST; + DST = do_div(tmp, (u32) SRC); +@@ -661,7 +661,7 @@ static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) + DST = div64_u64(DST, SRC); + CONT; + ALU_DIV_X: +- if (unlikely(SRC == 0)) ++ if (unlikely((u32)SRC == 0)) + return 0; + tmp = (u32) DST; + do_div(tmp, (u32) SRC); +-- +2.7.4 + |