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authorEric Dumazet <edumazet@google.com>2018-01-29 02:48:59 +0100
committerMichael Bestas <mkbestas@lineageos.org>2022-04-19 00:51:21 +0300
commit0d9c494ce097a84de4ff4993312b31ee43959d5b (patch)
tree679c664690b10a46275ddcd0d5af7de078c3cd61 /kernel/bpf/core.c
parent27ccd8a0afe3d42e62d8804182ca38ba33020e30 (diff)
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> Signed-off-by: Chatur27 <jasonbright2709@gmail.com>
Diffstat (limited to 'kernel/bpf/core.c')
-rw-r--r--kernel/bpf/core.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 64c4b13952f0..879ca844ba1d 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -642,7 +642,7 @@ select_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 @@ select_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);