From: Greg Kroah-Hartman Date: Sat, 23 May 2026 09:08:54 +0000 (+0200) Subject: drop queue-6.6/net-skbuff-propagate-shared-frag-marker-through-frag-transfer-helpers... X-Git-Tag: v6.6.141~10 X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=bd8a83b325d9d53de34536e3e0fc62303bd8d9b8;p=thirdparty%2Fkernel%2Fstable-queue.git drop queue-6.6/net-skbuff-propagate-shared-frag-marker-through-frag-transfer-helpers.patch --- diff --git a/queue-6.6/net-skbuff-propagate-shared-frag-marker-through-frag-transfer-helpers.patch b/queue-6.6/net-skbuff-propagate-shared-frag-marker-through-frag-transfer-helpers.patch deleted file mode 100644 index ef7d4ccf8e..0000000000 --- a/queue-6.6/net-skbuff-propagate-shared-frag-marker-through-frag-transfer-helpers.patch +++ /dev/null @@ -1,144 +0,0 @@ -From 48f6a5356a33dd78e7144ae1faef95ffc990aae0 Mon Sep 17 00:00:00 2001 -From: Hyunwoo Kim -Date: Sat, 16 May 2026 07:28:53 +0900 -Subject: net: skbuff: propagate shared-frag marker through frag-transfer helpers - -From: Hyunwoo Kim - -commit 48f6a5356a33dd78e7144ae1faef95ffc990aae0 upstream. - -Two frag-transfer helpers (__pskb_copy_fclone() and skb_shift()) fail -to propagate the SKBFL_SHARED_FRAG bit in skb_shinfo()->flags when -moving frags from source to destination. __pskb_copy_fclone() defers -the rest of the shinfo metadata to skb_copy_header() after copying -frag descriptors, but that helper only carries over gso_{size,segs, -type} and never touches skb_shinfo()->flags; skb_shift() moves frag -descriptors directly and leaves flags untouched. 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 ' 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. - -The same omission exists in skb_gro_receive() and skb_gro_receive_list(). -The former moves the incoming skb's frag descriptors into the -accumulator's last sub-skb via two paths (a direct frag-move loop and -the head_frag + memcpy path); 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. - -The same omission also exists in tcp_clone_payload(), which builds an -MTU probe skb by moving frag descriptors from skbs on sk_write_queue -into a freshly allocated nskb. The helper falls into the same family -and warrants the same fix for consistency; no TCP TX-side in-place -writer is currently known to reach a user page through this gap, but -a future consumer depending on the marker would regress silently. - -The same omission exists in skb_segment(): the per-iteration flag -merge takes only head_skb's flag, and the inner switch that rebinds -frag_skb to list_skb on head_skb-frags exhaustion does not fold the -new frag_skb's flag into nskb. Fold frag_skb's flag at both sites -so segments drawing frags from frag_list members carry the marker. - -Fixes: cef401de7be8 ("net: fix possible wrong checksum generation") -Fixes: f4c50a4034e6 ("xfrm: esp: avoid in-place decrypt on shared skb frags") -Suggested-by: Sabrina Dubroca -Suggested-by: Sultan Alsawaf -Suggested-by: Ben Hutchings -Suggested-by: Lin Ma -Suggested-by: Jingguo Tan -Suggested-by: Aaron Esau -Cc: stable@vger.kernel.org -Signed-off-by: Hyunwoo Kim -Tested-by: Rajat Gupta -Link: https://patch.msgid.link/ageeJfJHwgzmKXbh@v4bel -Signed-off-by: Paolo Abeni -Signed-off-by: Greg Kroah-Hartman ---- - net/core/gro.c | 5 +++++ - net/core/skbuff.c | 9 ++++++++- - net/ipv4/tcp_output.c | 1 + - 3 files changed, 14 insertions(+), 1 deletion(-) - ---- a/net/core/gro.c -+++ b/net/core/gro.c -@@ -216,11 +216,16 @@ done: - 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; - } -+ -+ skb_shinfo(p)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; -+ - NAPI_GRO_CB(skb)->same_flow = 1; - return 0; - } ---- a/net/core/skbuff.c -+++ b/net/core/skbuff.c -@@ -2050,6 +2050,7 @@ struct sk_buff *__pskb_copy_fclone(struc - 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)) { -@@ -4086,6 +4087,8 @@ onlymerged: - tgt->ip_summed = CHECKSUM_PARTIAL; - skb->ip_summed = CHECKSUM_PARTIAL; - -+ skb_shinfo(tgt)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; -+ - skb_len_add(skb, -shiftlen); - skb_len_add(tgt, shiftlen); - -@@ -4658,7 +4661,8 @@ normal: - skb_copy_from_linear_data_offset(head_skb, offset, - skb_put(nskb, hsize), hsize); - -- skb_shinfo(nskb)->flags |= skb_shinfo(head_skb)->flags & -+ skb_shinfo(nskb)->flags |= (skb_shinfo(head_skb)->flags | -+ skb_shinfo(frag_skb)->flags) & - SKBFL_SHARED_FRAG; - - if (skb_zerocopy_clone(nskb, frag_skb, GFP_ATOMIC)) -@@ -4675,6 +4679,9 @@ normal: - nfrags = skb_shinfo(list_skb)->nr_frags; - frag = skb_shinfo(list_skb)->frags; - frag_skb = list_skb; -+ -+ skb_shinfo(nskb)->flags |= skb_shinfo(frag_skb)->flags & SKBFL_SHARED_FRAG; -+ - if (!skb_headlen(list_skb)) { - BUG_ON(!nfrags); - } else { ---- a/net/ipv4/tcp_output.c -+++ b/net/ipv4/tcp_output.c -@@ -2366,6 +2366,7 @@ static int tcp_clone_payload(struct sock - todo = min_t(int, skb_frag_size(fragfrom), - probe_size - len); - len += todo; -+ skb_shinfo(to)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; - if (lastfrag && - skb_frag_page(fragfrom) == skb_frag_page(lastfrag) && - skb_frag_off(fragfrom) == skb_frag_off(lastfrag) + diff --git a/queue-6.6/series b/queue-6.6/series index 78684211e1..fefb7eb67d 100644 --- a/queue-6.6/series +++ b/queue-6.6/series @@ -507,4 +507,3 @@ mptcp-pm-add_addr-rtx-fix-potential-data-race.patch mptcp-pm-add_addr-rtx-resched-blocked-add_addr-quicker.patch net-rds-reset-op_nents-when-zerocopy-page-pin-fails.patch net-skbuff-preserve-shared-frag-marker-during-coalescing.patch -net-skbuff-propagate-shared-frag-marker-through-frag-transfer-helpers.patch