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authorAnton Protopopov <aspsk@isovalent.com>2024-12-10 11:42:45 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-01-09 13:23:36 +0100
commitf960a6b5d9bcb4437908c44f22894d33ebe284a3 (patch)
tree52f2c8bac275c6fcfa040459894c72c8007d4130 /kernel
parent892949259442d9968a07eb93f7b96ea2d9168d14 (diff)
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bpf: fix potential error return
[ Upstream commit c4441ca86afe4814039ee1b32c39d833c1a16bbc ] The bpf_remove_insns() function returns WARN_ON_ONCE(error), where error is a result of bpf_adj_branches(), and thus should be always 0 However, if for any reason it is not 0, then it will be converted to boolean by WARN_ON_ONCE and returned to user space as 1, not an actual error value. Fix this by returning the original err after the WARN check. Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241210114245.836164-1-aspsk@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/core.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index dde21d23f220..9fb103426cf0 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -496,6 +496,8 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
{
+ int err;
+
/* Branch offsets can't overflow when program is shrinking, no need
* to call bpf_adj_branches(..., true) here
*/
@@ -503,7 +505,9 @@ int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
sizeof(struct bpf_insn) * (prog->len - off - cnt));
prog->len -= cnt;
- return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
+ err = bpf_adj_branches(prog, off, off + cnt, off, false);
+ WARN_ON_ONCE(err);
+ return err;
}
static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)