From: Eric Dumazet <edumazet@google.com> stable inclusion from stable-v5.10.260 commit 71a20d1cf6efc97f9f6ea9ae33a061559202729e category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16159 CVE: CVE-2026-63830 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 5a8fb33e530512ee67a11b30f3451a4f030f4b01 ] We have plans for increasing MAX_SKB_FRAGS, but sk_msg_sg::copy is currently an unsigned long, limiting MAX_SKB_FRAGS to 30 on 32bit arches. Convert it to a bitmap, as Jakub suggested. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: 406e8a651a7b ("net: skmsg: preserve sg.copy across SG transforms") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- include/linux/skmsg.h | 11 +++++------ net/core/filter.c | 4 ++-- 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 86672847aa0a..594524e87e58 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -30,7 +30,7 @@ struct sk_msg_sg { u32 end; u32 size; u32 copybreak; - unsigned long copy; + DECLARE_BITMAP(copy, MAX_MSG_FRAGS + 2); /* The extra two elements: * 1) used for chaining the front and sections when the list becomes * partitioned (e.g. end < start). The crypto APIs require the @@ -39,7 +39,6 @@ struct sk_msg_sg { */ struct scatterlist data[MAX_MSG_FRAGS + 2]; }; -static_assert(BITS_PER_LONG >= NR_MSG_FRAG_IDS); /* UAPI in filter.c depends on struct sk_msg_sg being first element. */ struct sk_msg { @@ -247,7 +246,7 @@ static inline void sk_msg_compute_data_pointers(struct sk_msg *msg) { struct scatterlist *sge = sk_msg_elem(msg, msg->sg.start); - if (test_bit(msg->sg.start, &msg->sg.copy)) { + if (test_bit(msg->sg.start, msg->sg.copy)) { msg->data = NULL; msg->data_end = NULL; } else { @@ -266,7 +265,7 @@ static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page, sg_set_page(sge, page, len, offset); sg_unmark_end(sge); - __set_bit(msg->sg.end, &msg->sg.copy); + __set_bit(msg->sg.end, msg->sg.copy); msg->sg.size += len; sk_msg_iter_next(msg, end); } @@ -275,9 +274,9 @@ static inline void sk_msg_sg_copy(struct sk_msg *msg, u32 i, bool copy_state) { do { if (copy_state) - __set_bit(i, &msg->sg.copy); + __set_bit(i, msg->sg.copy); else - __clear_bit(i, &msg->sg.copy); + __clear_bit(i, msg->sg.copy); sk_msg_iter_var_next(i); if (i == msg->sg.end) break; diff --git a/net/core/filter.c b/net/core/filter.c index ef4e48cb2ee7..553b9e6fb16e 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2651,7 +2651,7 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start, * account for the headroom. */ bytes_sg_total = start - offset + bytes; - if (!test_bit(i, &msg->sg.copy) && bytes_sg_total <= len) + if (!test_bit(i, msg->sg.copy) && bytes_sg_total <= len) goto out; /* At this point we need to linearize multiple scatterlist @@ -2874,7 +2874,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start, /* Place newly allocated data buffer */ sk_mem_charge(msg->sk, len); msg->sg.size += len; - __clear_bit(new, &msg->sg.copy); + __clear_bit(new, msg->sg.copy); sg_set_page(&msg->sg.data[new], page, len + copy, 0); if (rsge.length) { get_page(sg_page(&rsge)); -- 2.43.0