diff --git a/SOURCES/1102-net-skbuff-propagate-shared-frag-marker.patch b/SOURCES/1102-net-skbuff-propagate-shared-frag-marker.patch new file mode 100644 index 000000000..cecaf98dd --- /dev/null +++ b/SOURCES/1102-net-skbuff-propagate-shared-frag-marker.patch @@ -0,0 +1,65 @@ +From: Andrew Lukoshko +Subject: [PATCH AlmaLinux 9] 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 already shipped as +1100-xfrm-esp-avoid-in-place-decrypt-shared-skb-frags.patch in +5.14.0-611.54.2). + +__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-5.14.0-611.54.1.el9_7. + +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 +@@ -2026,6 +2026,7 @@ 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)) { +@@ -5740,6 +5741,8 @@ 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/SPECS/kernel.spec b/SPECS/kernel.spec index 3b2b63a30..ffa16124e 100644 --- a/SPECS/kernel.spec +++ b/SPECS/kernel.spec @@ -165,13 +165,13 @@ Summary: The Linux kernel # define buildid .local %define specversion 5.14.0 %define patchversion 5.14 -%define pkgrelease 611.54.3 +%define pkgrelease 611.54.4 %define kversion 5 %define tarfile_release 5.14.0-611.54.1.el9_7 # This is needed to do merge window version magic %define patchlevel 14 # This allows pkg_release to have configurable %%{?dist} tag -%define specrelease 611.54.3%{?buildid}%{?dist} +%define specrelease 611.54.4%{?buildid}%{?dist} # This defines the kabi tarball version %define kabiversion 5.14.0-611.54.1.el9_7 @@ -958,6 +958,7 @@ Patch2006: 0006-Bring-back-deprecated-pci-ids-to-qla4xxx-driver.patch Patch2007: 0007-Bring-back-deprecated-pci-ids-to-be2iscsi-driver.patch Patch1100: 1100-xfrm-esp-avoid-in-place-decrypt-shared-skb-frags.patch Patch1101: 1101-rxrpc-linearize-paged-frags.patch +Patch1102: 1102-net-skbuff-propagate-shared-frag-marker.patch Patch11111: ppc64le-kvm-support.patch @@ -1704,6 +1705,7 @@ ApplyPatch 0006-Bring-back-deprecated-pci-ids-to-qla4xxx-driver.patch ApplyPatch 0007-Bring-back-deprecated-pci-ids-to-be2iscsi-driver.patch ApplyPatch 1100-xfrm-esp-avoid-in-place-decrypt-shared-skb-frags.patch ApplyPatch 1101-rxrpc-linearize-paged-frags.patch +ApplyPatch 1102-net-skbuff-propagate-shared-frag-marker.patch # END OF PATCH APPLICATIONS @@ -3775,6 +3777,9 @@ fi # # %changelog +* Wed May 13 2026 Andrew Lukoshko - 5.14.0-611.54.4 +- net: skbuff: propagate shared-frag marker through pskb_copy() + * Thu May 07 2026 Andrew Lukoshko - 5.14.0-611.54.3 - rxrpc: linearize incoming DATA packet when it has paged frags