lkml.org 
[lkml]   [2022]   [Oct]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.15 171/530] bpf: btf: fix truncated last_member_type_id in btf_struct_resolve
    Date
    From: Lorenz Bauer <oss@lmb.io>

    [ Upstream commit a37a32583e282d8d815e22add29bc1e91e19951a ]

    When trying to finish resolving a struct member, btf_struct_resolve
    saves the member type id in a u16 temporary variable. This truncates
    the 32 bit type id value if it exceeds UINT16_MAX.

    As a result, structs that have members with type ids > UINT16_MAX and
    which need resolution will fail with a message like this:

    [67414] STRUCT ff_device size=120 vlen=12
    effect_owners type_id=67434 bits_offset=960 Member exceeds struct_size

    Fix this by changing the type of last_member_type_id to u32.

    Fixes: a0791f0df7d2 ("bpf: fix BTF limits")
    Reviewed-by: Stanislav Fomichev <sdf@google.com>
    Signed-off-by: Lorenz Bauer <oss@lmb.io>
    Link: https://lore.kernel.org/r/20220910110120.339242-1-oss@lmb.io
    Signed-off-by: Alexei Starovoitov <ast@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    kernel/bpf/btf.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
    index 3cfba41a0829..7cb13b9f69a6 100644
    --- a/kernel/bpf/btf.c
    +++ b/kernel/bpf/btf.c
    @@ -2983,7 +2983,7 @@ static int btf_struct_resolve(struct btf_verifier_env *env,
    if (v->next_member) {
    const struct btf_type *last_member_type;
    const struct btf_member *last_member;
    - u16 last_member_type_id;
    + u32 last_member_type_id;

    last_member = btf_type_member(v->t) + v->next_member - 1;
    last_member_type_id = last_member->type;
    --
    2.35.1


    \
     
     \ /
      Last update: 2022-10-24 15:51    [W:4.035 / U:0.036 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site