diff --git a/1100-net-skbuff-propagate-shared-frag-marker.patch b/1100-net-skbuff-propagate-shared-frag-marker.patch new file mode 100644 index 000000000..03b8c5397 --- /dev/null +++ b/1100-net-skbuff-propagate-shared-frag-marker.patch @@ -0,0 +1,64 @@ +From: Andrew Lukoshko +Subject: [PATCH AlmaLinux 10] net: skbuff: propagate shared-frag marker through pskb_copy() + +Backport of upstream patch posted at +https://lore.kernel.org/all/agRfuVOeMI5pbHhY@v4bel/ +(sibling to the xfrm/esp shared-frag fix upstream commit f4c50a4034e6, +already merged into 6.12.0-124.56.1 via the c10s import). + +__pskb_copy_fclone() shallow-copies the source's frag descriptors and +bumps each page's refcount via skb_frag_ref(), then defers the rest +of the shinfo metadata to skb_copy_header(). That helper only carries +over gso_{size,segs,type} and never touches skb_shinfo()->flags, so +the destination skb keeps a reference to the same externally-owned or +page-cache-backed pages while reporting skb_has_shared_frag() as +false. + +The mismatch is harmful in any in-place writer that uses +skb_has_shared_frag() to decide whether shared pages must be detoured +through skb_cow_data(). ESP input is one such writer (esp4.c, +esp6.c), and a single nft 'dup to ' rule -- or any other +nf_dup_ipv4() / xt_TEE caller -- is enough to land a pskb_copy()'d +skb in esp_input() with the marker stripped, letting an unprivileged +user write into the page cache of a root-owned read-only file via +authencesn-ESN stray writes. + +Set SKBFL_SHARED_FRAG on the destination whenever frag descriptors +were actually moved from the source. skb_copy() and skb_copy_expand() +share skb_copy_header() too but linearize all paged data into freshly +allocated head storage and emerge with nr_frags == 0, so +skb_has_shared_frag() returns false on its own; they need no change. + +Verified to apply with `patch -p1 -F0` (no offset, no fuzz, no rejects) +against kernel-6.12.0-124.56.1.el10_1. + +Fixes: cef401de7be8 ("net: fix possible wrong checksum generation") +Fixes: f4c50a4034e6 ("xfrm: esp: avoid in-place decrypt on shared skb frags") +Reported-by: William Bowling +Reported-by: Hyunwoo Kim +Signed-off-by: Andrew Lukoshko +--- + net/core/skbuff.c | 3 +++ + 1 file changed, 3 insertions(+) + +--- a/net/core/skbuff.c ++++ b/net/core/skbuff.c +@@ -2123,6 +2123,7 @@ struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom, + skb_frag_ref(skb, i); + } + skb_shinfo(n)->nr_frags = i; ++ skb_shinfo(n)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; + } + + if (skb_has_frag_list(skb)) { +@@ -6028,6 +6029,8 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, + from_shinfo->frags, + from_shinfo->nr_frags * sizeof(skb_frag_t)); + to_shinfo->nr_frags += from_shinfo->nr_frags; ++ if (from_shinfo->nr_frags) ++ to_shinfo->flags |= from_shinfo->flags & SKBFL_SHARED_FRAG; + + if (!skb_cloned(from)) + from_shinfo->nr_frags = 0; +-- +2.43.0 diff --git a/kernel.spec b/kernel.spec index 3217e8de7..d8830e770 100644 --- a/kernel.spec +++ b/kernel.spec @@ -176,13 +176,13 @@ Summary: The Linux kernel %define specrpmversion 6.12.0 %define specversion 6.12.0 %define patchversion 6.12 -%define pkgrelease 124.56.1 +%define pkgrelease 124.56.2 %define kversion 6 %define tarfile_release 6.12.0-124.56.1.el10_1 # This is needed to do merge window version magic %define patchlevel 12 # This allows pkg_release to have configurable %%{?dist} tag -%define specrelease 124.56.1%{?buildid}%{?dist} +%define specrelease 124.56.2%{?buildid}%{?dist} # This defines the kabi tarball version %define kabiversion 6.12.0-124.56.1.el10_1 @@ -1128,6 +1128,7 @@ Patch2007: 0007-Bring-back-deprecated-pci-ids-to-be2iscsi-driver.patch Patch2008: 0008-Bring-back-deprecated-pci-ids-to-megaraid_sas-driver.patch Patch2009: 0009-Bring-back-deprecated-pci-ids-to-mpt3sas-driver.patch Patch2010: 0010-Bring-back-deprecated-pci-ids-to-aacraid-driver.patch +Patch1100: 1100-net-skbuff-propagate-shared-frag-marker.patch # END OF PATCH DEFINITIONS @@ -1989,6 +1990,7 @@ ApplyPatch 0007-Bring-back-deprecated-pci-ids-to-be2iscsi-driver.patch ApplyPatch 0008-Bring-back-deprecated-pci-ids-to-megaraid_sas-driver.patch ApplyPatch 0009-Bring-back-deprecated-pci-ids-to-mpt3sas-driver.patch ApplyPatch 0010-Bring-back-deprecated-pci-ids-to-aacraid-driver.patch +ApplyPatch 1100-net-skbuff-propagate-shared-frag-marker.patch %{log_msg "End of patch applications"} # END OF PATCH APPLICATIONS @@ -4377,6 +4379,9 @@ fi\ # # %changelog +* Wed May 13 2026 Andrew Lukoshko - 6.12.0-124.56.2 +- net: skbuff: propagate shared-frag marker through pskb_copy() + * Wed May 13 2026 Eduard Abdullin - 6.12.0-124.56.1 - Debrand for AlmaLinux OS - Use AlmaLinux OS secure boot cert