Bump version to 5.14.0-611.54.5

net: skbuff: propagate shared-frag marker through frag-transfer helpers

Replace 611.54.4's partial fix (which was a backport of Hyunwoo Kim's
v1 patch covering only __pskb_copy_fclone() and skb_try_coalesce())
with a backport of the upstream v3 patch:
https://lore.kernel.org/all/agW4vC0r8QOUKtRT@v4bel/

v3 also covers skb_shift() (the new hunk added in v2) and
skb_gro_receive() / skb_gro_receive_list() (the audit follow-up
suggested by Sultan Alsawaf in agVpIsaSherjHTYg@sultan-box).

All five sites moved frag descriptors between skbs without
propagating the SKBFL_SHARED_FRAG marker, so destinations could end
up referencing externally-owned or page-cache-backed pages while
reporting skb_has_shared_frag() as false. Combined with ESP-over-UDP
and UDP GRO, or any nf_dup_ipv4 / xt_TEE caller, this lets an
unprivileged user trigger in-place ESP decryption over root-owned
page-cache pages (CVE-2026-46300, "Fragnesia").

Tree-adapted: skb_gro_receive_list() is still a static helper in
net/ipv4/udp_offload.c on RHEL 9 (not promoted to a global GRO
helper in net/core/gro.c as in upstream v3); skb_shift() still uses
the open-coded skb->len -= shiftlen block instead of skb_len_add().

SOURCES/1102-net-skbuff-propagate-shared-frag-marker.patch

@@ -1,28 +1,30 @@
-From: Andrew Lukoshko <alukoshko@almalinux.org>
+From: Eduard Abdullin <eabdullin@almalinux.org>
-Subject: [PATCH AlmaLinux 9] net: skbuff: propagate shared-frag marker through pskb_copy()
+Subject: [PATCH AlmaLinux 9] net: skbuff: propagate shared-frag marker through frag-transfer helpers
 
-Backport of upstream patch posted at
+Backport of upstream v3 patch posted at
-https://lore.kernel.org/all/agRfuVOeMI5pbHhY@v4bel/
+https://lore.kernel.org/all/agW4vC0r8QOUKtRT@v4bel/
-(sibling to the xfrm/esp shared-frag fix already shipped as
+(sibling to upstream commit f4c50a4034e6 "xfrm: esp: avoid in-place
-1100-xfrm-esp-avoid-in-place-decrypt-shared-skb-frags.patch in
+decrypt on shared skb frags").
-5.14.0-611.54.2).
 
-__pskb_copy_fclone() shallow-copies the source's frag descriptors and
+Three frag-transfer helpers in net/core/skbuff.c
-bumps each page's refcount via skb_frag_ref(), then defers the rest
+(__pskb_copy_fclone(), skb_try_coalesce(), skb_shift()) and the
-of the shinfo metadata to skb_copy_header().  That helper only carries
+GRO accumulator path in net/core/gro.c (skb_gro_receive()) and the
-over gso_{size,segs,type} and never touches skb_shinfo()->flags, so
+UDP GRO list helper in net/ipv4/udp_offload.c
-the destination skb keeps a reference to the same externally-owned or
+(skb_gro_receive_list(), kept as a static helper on AlmaLinux 9)
-page-cache-backed pages while reporting skb_has_shared_frag() as
+fail to propagate the SKBFL_SHARED_FRAG bit in skb_shinfo()->flags
-false.
+when moving frag descriptors from source to destination.  As a
+result, 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 <local>' rule -- or any other
+esp6.c).  Combined with an nft 'dup to <local>' rule, an
-nf_dup_ipv4() / xt_TEE caller -- is enough to land a pskb_copy()'d
+nf_dup_ipv4() / xt_TEE caller, or ESP-over-UDP with UDP GRO, this
-skb in esp_input() with the marker stripped, letting an unprivileged
+lets an unprivileged user write into the page cache of a root-owned
-user write into the page cache of a root-owned read-only file via
+read-only file via authencesn-ESN stray writes (CVE-2026-46300,
-authencesn-ESN stray writes.
+"Fragnesia").
 
 Set SKBFL_SHARED_FRAG on the destination whenever frag descriptors
 were actually moved from the source.  skb_copy() and skb_copy_expand()
@@ -30,18 +32,53 @@ 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)
+The same omission exists in skb_gro_receive() and
-against kernel-5.14.0-611.54.1.el9_7.
+skb_gro_receive_list().  The former moves the incoming skb's frag
+descriptors into the accumulator's last sub-skb via two paths plus a
+"merge:" fallback that chains the whole skb onto frag_list; the
+latter chains the incoming skb whole onto p's frag_list.  Downstream
+skb_segment() reads only skb_shinfo(p)->flags, and skb_segment_list()
+reuses each sub-skb's shinfo as the nskb -- both p and lp must carry
+the marker.
+
+Tree adaptation:
+  * Upstream v3 places skb_gro_receive_list() in net/core/gro.c.
+    AlmaLinux 9 still keeps it as a static helper in
+    net/ipv4/udp_offload.c (it has not been promoted to a global
+    GRO helper in this tree).  Apply the propagation hunk there
+    instead.
+  * Upstream skb_shift() uses skb_len_add() helpers (introduced in
+    v5.16); AlmaLinux 9 still has the open-coded
+    `skb->len -= shiftlen; ...` block.  The insertion point (right
+    after both ip_summed assignments) is the same.
 
 Fixes: cef401de7be8 ("net: fix possible wrong checksum generation")
 Fixes: f4c50a4034e6 ("xfrm: esp: avoid in-place decrypt on shared skb frags")
+Reported-by: Sultan Alsawaf <sultan@kerneltoast.com>
 Reported-by: William Bowling <vakzz@zellic.io>
 Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
-Signed-off-by: Andrew Lukoshko <alukoshko@almalinux.org>
+Signed-off-by: Eduard Abdullin <eabdullin@almalinux.org>
 ---
- net/core/skbuff.c | 3 +++
+ net/core/gro.c         | 2 ++
- 1 file changed, 3 insertions(+)
+ net/core/skbuff.c      | 6 ++++++
+ net/ipv4/udp_offload.c | 2 ++
+ 3 files changed, 10 insertions(+)
 
+--- a/net/core/gro.c
++++ b/net/core/gro.c
+@@ -222,10 +222,12 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
+ 	p->data_len += len;
+ 	p->truesize += delta_truesize;
+ 	p->len += len;
++	skb_shinfo(p)->flags |= skbinfo->flags & SKBFL_SHARED_FRAG;
+ 	if (lp != p) {
+ 		lp->data_len += len;
+ 		lp->truesize += delta_truesize;
+ 		lp->len += len;
++		skb_shinfo(lp)->flags |= skbinfo->flags & SKBFL_SHARED_FRAG;
+ 	}
+ 	NAPI_GRO_CB(skb)->same_flow = 1;
+ 	return 0;
 --- 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,
@@ -52,7 +89,16 @@ Signed-off-by: Andrew Lukoshko <alukoshko@almalinux.org>
  	}
 
  	if (skb_has_frag_list(skb)) {
-@@ -5740,6 +5741,8 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
+@@ -4029,6 +4030,8 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen)
+ 	tgt->ip_summed = CHECKSUM_PARTIAL;
+ 	skb->ip_summed = CHECKSUM_PARTIAL;
+
++	skb_shinfo(tgt)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
++
+ 	/* Yak, is it really working this way? Some helper please? */
+ 	skb->len -= shiftlen;
+ 	skb->data_len -= shiftlen;
+@@ -5740,6 +5743,8 @@ 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;
@@ -61,5 +107,16 @@ Signed-off-by: Andrew Lukoshko <alukoshko@almalinux.org>
 
  	if (!skb_cloned(from))
  		from_shinfo->nr_frags = 0;
+--- a/net/ipv4/udp_offload.c
++++ b/net/ipv4/udp_offload.c
+@@ -487,6 +487,8 @@ static int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb)
+ 	p->truesize += skb->truesize;
+ 	p->len += skb->len;
+
++	skb_shinfo(p)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
++
+ 	NAPI_GRO_CB(skb)->same_flow = 1;
+
+ 	return 0;
 --
 2.43.0

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 611.54.4
+%define pkgrelease 611.54.5
 %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 611.54.4%{?buildid}%{?dist}
+%define specrelease 611.54.5%{?buildid}%{?dist}
 # This defines the kabi tarball version
 %define kabiversion 5.14.0-611.54.1.el9_7
 
@@ -3777,6 +3777,9 @@ fi
 #
 #
 %changelog
+* Thu May 14 2026 Eduard Abdullin <eabdullin@almalinux.org> - 5.14.0-611.54.5
+- net: skbuff: propagate shared-frag marker through frag-transfer helpers
+
 * Wed May 13 2026 Andrew Lukoshko <alukoshko@almalinux.org> - 5.14.0-611.54.4
 - net: skbuff: propagate shared-frag marker through pskb_copy()