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* FAILED: patch "[PATCH] net: skmsg: preserve sg.copy across SG transforms" failed to apply to 5.15-stable tree
@ 2026-07-02  8:27 gregkh
  2026-07-02 15:11 ` [PATCH 5.15.y 1/2] skmsg: convert struct sk_msg_sg::copy to a bitmap Sasha Levin
  0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2026-07-02  8:27 UTC (permalink / raw)
  To: yimingqian591, keenanat2000, kuba; +Cc: stable


The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 406e8a651a7b854c41fecd5117bb282b3a6c2c6b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026070245-deviation-chaffing-97e7@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 406e8a651a7b854c41fecd5117bb282b3a6c2c6b Mon Sep 17 00:00:00 2001
From: Yiming Qian <yimingqian591@gmail.com>
Date: Wed, 10 Jun 2026 06:21:36 +0000
Subject: [PATCH] net: skmsg: preserve sg.copy across SG transforms

The sk_msg sg.copy bitmap is part of the scatterlist entry ownership
state. A set bit tells sk_msg_compute_data_pointers() not to expose the
entry through writable BPF ctx->data. This protects entries backed by
pages that are not private to the sk_msg, such as splice-backed file
page-cache pages.

Several sk_msg transform paths move, copy, split, or compact
msg->sg.data[] entries without moving the matching sg.copy bit. This can
make an externally backed entry arrive at a new slot with a clear copy
bit. A later SK_MSG verdict can then expose sg_virt(sge) as writable
ctx->data and BPF stores can modify the original page cache.

Keep sg.copy synchronized with sg.data[] whenever entries are
transferred, shifted, split, or copied into a new sk_msg. Clear the bit
when an entry is replaced by a newly allocated private page or freed.
This covers the BPF pull/push/pop helpers, sk_msg_shift_left/right(),
sk_msg_xfer(), and tls_split_open_record(), including the partial tail
entry created during TLS open-record splitting.

Fixes: d3b18ad31f93 ("tls: add bpf support to sk_msg handling")
Cc: stable@vger.kernel.org
Reported-by: Yiming Qian <yimingqian591@gmail.com>
Reported-by: Keenan Dong <keenanat2000@gmail.com>
Signed-off-by: Yiming Qian <yimingqian591@gmail.com>
Link: https://patch.msgid.link/20260610062137.49075-1-yimingqian591@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index 19f4f253b4f9..937823856de5 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -4,6 +4,7 @@
 #ifndef _LINUX_SKMSG_H
 #define _LINUX_SKMSG_H
 
+#include <linux/bitops.h>
 #include <linux/bpf.h>
 #include <linux/filter.h>
 #include <linux/scatterlist.h>
@@ -199,11 +200,14 @@ static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src,
 			       int which, u32 size)
 {
 	dst->sg.data[which] = src->sg.data[which];
+	__assign_bit(which, dst->sg.copy, test_bit(which, src->sg.copy));
 	dst->sg.data[which].length  = size;
 	dst->sg.size		   += size;
 	src->sg.size		   -= size;
 	src->sg.data[which].length -= size;
 	src->sg.data[which].offset += size;
+	if (!src->sg.data[which].length)
+		__clear_bit(which, src->sg.copy);
 }
 
 static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src)
@@ -273,16 +277,19 @@ static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page,
 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);
-		else
-			__clear_bit(i, msg->sg.copy);
+		__assign_bit(i, msg->sg.copy, copy_state);
 		sk_msg_iter_var_next(i);
 		if (i == msg->sg.end)
 			break;
 	} while (1);
 }
 
+static inline void sk_msg_sg_copy_assign(struct sk_msg *dst, u32 dst_i,
+					 const struct sk_msg *src, u32 src_i)
+{
+	__assign_bit(dst_i, dst->sg.copy, test_bit(src_i, src->sg.copy));
+}
+
 static inline void sk_msg_sg_copy_set(struct sk_msg *msg, u32 start)
 {
 	sk_msg_sg_copy(msg, start, true);
diff --git a/net/core/filter.c b/net/core/filter.c
index 80439767e0ee..40037413dd4e 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2733,11 +2733,13 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
 		poffset += len;
 		sge->length = 0;
 		put_page(sg_page(sge));
+		__clear_bit(i, msg->sg.copy);
 
 		sk_msg_iter_var_next(i);
 	} while (i != last_sge);
 
 	sg_set_page(&msg->sg.data[first_sge], page, copy, 0);
+	__clear_bit(first_sge, msg->sg.copy);
 
 	/* To repair sg ring we need to shift entries. If we only
 	 * had a single entry though we can just replace it and
@@ -2763,9 +2765,11 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
 			break;
 
 		msg->sg.data[i] = msg->sg.data[move_from];
+		sk_msg_sg_copy_assign(msg, i, msg, move_from);
 		msg->sg.data[move_from].length = 0;
 		msg->sg.data[move_from].page_link = 0;
 		msg->sg.data[move_from].offset = 0;
+		__clear_bit(move_from, msg->sg.copy);
 		sk_msg_iter_var_next(i);
 	} while (1);
 
@@ -2794,6 +2798,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 {
 	struct scatterlist sge, nsge, nnsge, rsge = {0}, *psge;
 	u32 new, i = 0, l = 0, space, copy = 0, offset = 0;
+	bool sge_copy, nsge_copy, nnsge_copy, rsge_copy = false;
 	u8 *raw, *to, *from;
 	struct page *page;
 
@@ -2866,6 +2871,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 			sk_msg_iter_var_prev(i);
 		psge = sk_msg_elem(msg, i);
 		rsge = sk_msg_elem_cpy(msg, i);
+		rsge_copy = test_bit(i, msg->sg.copy);
 
 		psge->length = start - offset;
 		rsge.length -= psge->length;
@@ -2890,24 +2896,32 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 
 	/* Shift one or two slots as needed */
 	sge = sk_msg_elem_cpy(msg, new);
+	sge_copy = test_bit(new, msg->sg.copy);
 	sg_unmark_end(&sge);
 
 	nsge = sk_msg_elem_cpy(msg, i);
+	nsge_copy = test_bit(i, msg->sg.copy);
 	if (rsge.length) {
 		sk_msg_iter_var_next(i);
 		nnsge = sk_msg_elem_cpy(msg, i);
+		nnsge_copy = test_bit(i, msg->sg.copy);
 		sk_msg_iter_next(msg, end);
 	}
 
 	while (i != msg->sg.end) {
 		msg->sg.data[i] = sge;
+		__assign_bit(i, msg->sg.copy, sge_copy);
 		sge = nsge;
+		sge_copy = nsge_copy;
 		sk_msg_iter_var_next(i);
 		if (rsge.length) {
 			nsge = nnsge;
+			nsge_copy = nnsge_copy;
 			nnsge = sk_msg_elem_cpy(msg, i);
+			nnsge_copy = test_bit(i, msg->sg.copy);
 		} else {
 			nsge = sk_msg_elem_cpy(msg, i);
+			nsge_copy = test_bit(i, msg->sg.copy);
 		}
 	}
 
@@ -2921,6 +2935,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 		get_page(sg_page(&rsge));
 		sk_msg_iter_var_next(new);
 		msg->sg.data[new] = rsge;
+		__assign_bit(new, msg->sg.copy, rsge_copy);
 	}
 
 	sk_msg_reset_curr(msg);
@@ -2948,25 +2963,33 @@ static void sk_msg_shift_left(struct sk_msg *msg, int i)
 		prev = i;
 		sk_msg_iter_var_next(i);
 		msg->sg.data[prev] = msg->sg.data[i];
+		sk_msg_sg_copy_assign(msg, prev, msg, i);
 	} while (i != msg->sg.end);
 
 	sk_msg_iter_prev(msg, end);
+	__clear_bit(msg->sg.end, msg->sg.copy);
 }
 
 static void sk_msg_shift_right(struct sk_msg *msg, int i)
 {
 	struct scatterlist tmp, sge;
+	bool tmp_copy, sge_copy;
 
 	sk_msg_iter_next(msg, end);
 	sge = sk_msg_elem_cpy(msg, i);
+	sge_copy = test_bit(i, msg->sg.copy);
 	sk_msg_iter_var_next(i);
 	tmp = sk_msg_elem_cpy(msg, i);
+	tmp_copy = test_bit(i, msg->sg.copy);
 
 	while (i != msg->sg.end) {
 		msg->sg.data[i] = sge;
+		__assign_bit(i, msg->sg.copy, sge_copy);
 		sk_msg_iter_var_next(i);
 		sge = tmp;
+		sge_copy = tmp_copy;
 		tmp = sk_msg_elem_cpy(msg, i);
+		tmp_copy = test_bit(i, msg->sg.copy);
 	}
 }
 
@@ -3026,6 +3049,8 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 		struct scatterlist *nsge, *sge = sk_msg_elem(msg, i);
 		int a = start - offset;
 		int b = sge->length - pop - a;
+		u32 sge_i = i;
+		bool sge_copy = test_bit(i, msg->sg.copy);
 
 		sk_msg_iter_var_next(i);
 
@@ -3038,6 +3063,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				sg_set_page(nsge,
 					    sg_page(sge),
 					    b, sge->offset + pop + a);
+				__assign_bit(i, msg->sg.copy, sge_copy);
 			} else {
 				struct page *page, *orig;
 				u8 *to, *from;
@@ -3054,6 +3080,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				memcpy(to, from, a);
 				memcpy(to + a, from + a + pop, b);
 				sg_set_page(sge, page, a + b, 0);
+				__clear_bit(sge_i, msg->sg.copy);
 				put_page(orig);
 			}
 			pop = 0;
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index e1850caf1a71..30c3b9a2681c 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -66,6 +66,7 @@ int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
 			sge = &msg->sg.data[msg->sg.end];
 			sg_unmark_end(sge);
 			sg_set_page(sge, pfrag->page, use, orig_offset);
+			__clear_bit(msg->sg.end, msg->sg.copy);
 			get_page(pfrag->page);
 			sk_msg_iter_next(msg, end);
 		}
@@ -186,6 +187,7 @@ static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
 			sk_mem_uncharge(sk, len);
 		put_page(sg_page(sge));
 	}
+	__clear_bit(i, msg->sg.copy);
 	memset(sge, 0, sizeof(*sge));
 	return len;
 }
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 964ebc268ee4..a47f6a1e2c77 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -623,6 +623,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 	struct scatterlist *sge, *osge, *nsge;
 	u32 orig_size = msg_opl->sg.size;
 	struct scatterlist tmp = { };
+	u32 tmp_i = 0;
 	struct sk_msg *msg_npl;
 	struct tls_rec *new;
 	int ret;
@@ -644,6 +645,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 		if (sge->length > apply) {
 			u32 len = sge->length - apply;
 
+			tmp_i = i;
 			get_page(sg_page(sge));
 			sg_set_page(&tmp, sg_page(sge), len,
 				    sge->offset + apply);
@@ -675,6 +677,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 	nsge = sk_msg_elem(msg_npl, j);
 	if (tmp.length) {
 		memcpy(nsge, &tmp, sizeof(*nsge));
+		sk_msg_sg_copy_assign(msg_npl, j, msg_opl, tmp_i);
 		sk_msg_iter_var_next(j);
 		nsge = sk_msg_elem(msg_npl, j);
 	}
@@ -682,6 +685,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 	osge = sk_msg_elem(msg_opl, i);
 	while (osge->length) {
 		memcpy(nsge, osge, sizeof(*nsge));
+		sk_msg_sg_copy_assign(msg_npl, j, msg_opl, i);
 		sg_unmark_end(nsge);
 		sk_msg_iter_var_next(i);
 		sk_msg_iter_var_next(j);


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* [PATCH 5.15.y 1/2] skmsg: convert struct sk_msg_sg::copy to a bitmap
  2026-07-02  8:27 FAILED: patch "[PATCH] net: skmsg: preserve sg.copy across SG transforms" failed to apply to 5.15-stable tree gregkh
@ 2026-07-02 15:11 ` Sasha Levin
  2026-07-02 15:11   ` [PATCH 5.15.y 2/2] net: skmsg: preserve sg.copy across SG transforms Sasha Levin
  0 siblings, 1 reply; 3+ messages in thread
From: Sasha Levin @ 2026-07-02 15:11 UTC (permalink / raw)
  To: stable; +Cc: Eric Dumazet, David S. Miller, Sasha Levin

From: Eric Dumazet <edumazet@google.com>

[ 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>
---
 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 5d3e4d4d9438e2..7bc66fd7fc58c1 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -29,7 +29,7 @@ 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
@@ -38,7 +38,6 @@ 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 {
@@ -236,7 +235,7 @@ 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 {
@@ -255,7 +254,7 @@ 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);
 }
@@ -264,9 +263,9 @@ 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 6a1210abe4625e..5874ecb192098c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2660,7 +2660,7 @@ 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
@@ -2883,7 +2883,7 @@ 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));
-- 
2.53.0


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* [PATCH 5.15.y 2/2] net: skmsg: preserve sg.copy across SG transforms
  2026-07-02 15:11 ` [PATCH 5.15.y 1/2] skmsg: convert struct sk_msg_sg::copy to a bitmap Sasha Levin
@ 2026-07-02 15:11   ` Sasha Levin
  0 siblings, 0 replies; 3+ messages in thread
From: Sasha Levin @ 2026-07-02 15:11 UTC (permalink / raw)
  To: stable; +Cc: Yiming Qian, Keenan Dong, Jakub Kicinski, Sasha Levin

From: Yiming Qian <yimingqian591@gmail.com>

[ Upstream commit 406e8a651a7b854c41fecd5117bb282b3a6c2c6b ]

The sk_msg sg.copy bitmap is part of the scatterlist entry ownership
state. A set bit tells sk_msg_compute_data_pointers() not to expose the
entry through writable BPF ctx->data. This protects entries backed by
pages that are not private to the sk_msg, such as splice-backed file
page-cache pages.

Several sk_msg transform paths move, copy, split, or compact
msg->sg.data[] entries without moving the matching sg.copy bit. This can
make an externally backed entry arrive at a new slot with a clear copy
bit. A later SK_MSG verdict can then expose sg_virt(sge) as writable
ctx->data and BPF stores can modify the original page cache.

Keep sg.copy synchronized with sg.data[] whenever entries are
transferred, shifted, split, or copied into a new sk_msg. Clear the bit
when an entry is replaced by a newly allocated private page or freed.
This covers the BPF pull/push/pop helpers, sk_msg_shift_left/right(),
sk_msg_xfer(), and tls_split_open_record(), including the partial tail
entry created during TLS open-record splitting.

Fixes: d3b18ad31f93 ("tls: add bpf support to sk_msg handling")
Cc: stable@vger.kernel.org
Reported-by: Yiming Qian <yimingqian591@gmail.com>
Reported-by: Keenan Dong <keenanat2000@gmail.com>
Signed-off-by: Yiming Qian <yimingqian591@gmail.com>
Link: https://patch.msgid.link/20260610062137.49075-1-yimingqian591@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/linux/skmsg.h | 15 +++++++++++----
 net/core/filter.c     | 27 +++++++++++++++++++++++++++
 net/core/skmsg.c      |  2 ++
 net/tls/tls_sw.c      |  4 ++++
 4 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index 7bc66fd7fc58c1..fb0709d17fd2b1 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -4,6 +4,7 @@
 #ifndef _LINUX_SKMSG_H
 #define _LINUX_SKMSG_H
 
+#include <linux/bitops.h>
 #include <linux/bpf.h>
 #include <linux/filter.h>
 #include <linux/scatterlist.h>
@@ -188,11 +189,14 @@ static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src,
 			       int which, u32 size)
 {
 	dst->sg.data[which] = src->sg.data[which];
+	__assign_bit(which, dst->sg.copy, test_bit(which, src->sg.copy));
 	dst->sg.data[which].length  = size;
 	dst->sg.size		   += size;
 	src->sg.size		   -= size;
 	src->sg.data[which].length -= size;
 	src->sg.data[which].offset += size;
+	if (!src->sg.data[which].length)
+		__clear_bit(which, src->sg.copy);
 }
 
 static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src)
@@ -262,16 +266,19 @@ static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page,
 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);
-		else
-			__clear_bit(i, msg->sg.copy);
+		__assign_bit(i, msg->sg.copy, copy_state);
 		sk_msg_iter_var_next(i);
 		if (i == msg->sg.end)
 			break;
 	} while (1);
 }
 
+static inline void sk_msg_sg_copy_assign(struct sk_msg *dst, u32 dst_i,
+					 const struct sk_msg *src, u32 src_i)
+{
+	__assign_bit(dst_i, dst->sg.copy, test_bit(src_i, src->sg.copy));
+}
+
 static inline void sk_msg_sg_copy_set(struct sk_msg *msg, u32 start)
 {
 	sk_msg_sg_copy(msg, start, true);
diff --git a/net/core/filter.c b/net/core/filter.c
index 5874ecb192098c..2b413e9b6d02a6 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2701,11 +2701,13 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
 		poffset += len;
 		sge->length = 0;
 		put_page(sg_page(sge));
+		__clear_bit(i, msg->sg.copy);
 
 		sk_msg_iter_var_next(i);
 	} while (i != last_sge);
 
 	sg_set_page(&msg->sg.data[first_sge], page, copy, 0);
+	__clear_bit(first_sge, msg->sg.copy);
 
 	/* To repair sg ring we need to shift entries. If we only
 	 * had a single entry though we can just replace it and
@@ -2731,9 +2733,11 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
 			break;
 
 		msg->sg.data[i] = msg->sg.data[move_from];
+		sk_msg_sg_copy_assign(msg, i, msg, move_from);
 		msg->sg.data[move_from].length = 0;
 		msg->sg.data[move_from].page_link = 0;
 		msg->sg.data[move_from].offset = 0;
+		__clear_bit(move_from, msg->sg.copy);
 		sk_msg_iter_var_next(i);
 	} while (1);
 
@@ -2762,6 +2766,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 {
 	struct scatterlist sge, nsge, nnsge, rsge = {0}, *psge;
 	u32 new, i = 0, l = 0, space, copy = 0, offset = 0;
+	bool sge_copy, nsge_copy, nnsge_copy, rsge_copy = false;
 	u8 *raw, *to, *from;
 	struct page *page;
 
@@ -2834,6 +2839,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 			sk_msg_iter_var_prev(i);
 		psge = sk_msg_elem(msg, i);
 		rsge = sk_msg_elem_cpy(msg, i);
+		rsge_copy = test_bit(i, msg->sg.copy);
 
 		psge->length = start - offset;
 		rsge.length -= psge->length;
@@ -2858,24 +2864,32 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 
 	/* Shift one or two slots as needed */
 	sge = sk_msg_elem_cpy(msg, new);
+	sge_copy = test_bit(new, msg->sg.copy);
 	sg_unmark_end(&sge);
 
 	nsge = sk_msg_elem_cpy(msg, i);
+	nsge_copy = test_bit(i, msg->sg.copy);
 	if (rsge.length) {
 		sk_msg_iter_var_next(i);
 		nnsge = sk_msg_elem_cpy(msg, i);
+		nnsge_copy = test_bit(i, msg->sg.copy);
 		sk_msg_iter_next(msg, end);
 	}
 
 	while (i != msg->sg.end) {
 		msg->sg.data[i] = sge;
+		__assign_bit(i, msg->sg.copy, sge_copy);
 		sge = nsge;
+		sge_copy = nsge_copy;
 		sk_msg_iter_var_next(i);
 		if (rsge.length) {
 			nsge = nnsge;
+			nsge_copy = nnsge_copy;
 			nnsge = sk_msg_elem_cpy(msg, i);
+			nnsge_copy = test_bit(i, msg->sg.copy);
 		} else {
 			nsge = sk_msg_elem_cpy(msg, i);
+			nsge_copy = test_bit(i, msg->sg.copy);
 		}
 	}
 
@@ -2889,6 +2903,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 		get_page(sg_page(&rsge));
 		sk_msg_iter_var_next(new);
 		msg->sg.data[new] = rsge;
+		__assign_bit(new, msg->sg.copy, rsge_copy);
 	}
 
 	sk_msg_reset_curr(msg);
@@ -2916,25 +2931,33 @@ static void sk_msg_shift_left(struct sk_msg *msg, int i)
 		prev = i;
 		sk_msg_iter_var_next(i);
 		msg->sg.data[prev] = msg->sg.data[i];
+		sk_msg_sg_copy_assign(msg, prev, msg, i);
 	} while (i != msg->sg.end);
 
 	sk_msg_iter_prev(msg, end);
+	__clear_bit(msg->sg.end, msg->sg.copy);
 }
 
 static void sk_msg_shift_right(struct sk_msg *msg, int i)
 {
 	struct scatterlist tmp, sge;
+	bool tmp_copy, sge_copy;
 
 	sk_msg_iter_next(msg, end);
 	sge = sk_msg_elem_cpy(msg, i);
+	sge_copy = test_bit(i, msg->sg.copy);
 	sk_msg_iter_var_next(i);
 	tmp = sk_msg_elem_cpy(msg, i);
+	tmp_copy = test_bit(i, msg->sg.copy);
 
 	while (i != msg->sg.end) {
 		msg->sg.data[i] = sge;
+		__assign_bit(i, msg->sg.copy, sge_copy);
 		sk_msg_iter_var_next(i);
 		sge = tmp;
+		sge_copy = tmp_copy;
 		tmp = sk_msg_elem_cpy(msg, i);
+		tmp_copy = test_bit(i, msg->sg.copy);
 	}
 }
 
@@ -2994,6 +3017,8 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 		struct scatterlist *nsge, *sge = sk_msg_elem(msg, i);
 		int a = start - offset;
 		int b = sge->length - pop - a;
+		u32 sge_i = i;
+		bool sge_copy = test_bit(i, msg->sg.copy);
 
 		sk_msg_iter_var_next(i);
 
@@ -3006,6 +3031,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				sg_set_page(nsge,
 					    sg_page(sge),
 					    b, sge->offset + pop + a);
+				__assign_bit(i, msg->sg.copy, sge_copy);
 			} else {
 				struct page *page, *orig;
 				u8 *to, *from;
@@ -3022,6 +3048,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				memcpy(to, from, a);
 				memcpy(to + a, from + a + pop, b);
 				sg_set_page(sge, page, a + b, 0);
+				__clear_bit(sge_i, msg->sg.copy);
 				put_page(orig);
 			}
 			pop = 0;
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 68e5fd7aa12893..2bf60619dc7b25 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -65,6 +65,7 @@ int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
 			sge = &msg->sg.data[msg->sg.end];
 			sg_unmark_end(sge);
 			sg_set_page(sge, pfrag->page, use, orig_offset);
+			__clear_bit(msg->sg.end, msg->sg.copy);
 			get_page(pfrag->page);
 			sk_msg_iter_next(msg, end);
 		}
@@ -185,6 +186,7 @@ static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
 			sk_mem_uncharge(sk, len);
 		put_page(sg_page(sge));
 	}
+	__clear_bit(i, msg->sg.copy);
 	memset(sge, 0, sizeof(*sge));
 	return len;
 }
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 630fa387da14f0..389597bd7ae524 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -607,6 +607,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 	struct scatterlist *sge, *osge, *nsge;
 	u32 orig_size = msg_opl->sg.size;
 	struct scatterlist tmp = { };
+	u32 tmp_i = 0;
 	struct sk_msg *msg_npl;
 	struct tls_rec *new;
 	int ret;
@@ -628,6 +629,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 		if (sge->length > apply) {
 			u32 len = sge->length - apply;
 
+			tmp_i = i;
 			get_page(sg_page(sge));
 			sg_set_page(&tmp, sg_page(sge), len,
 				    sge->offset + apply);
@@ -659,6 +661,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 	nsge = sk_msg_elem(msg_npl, j);
 	if (tmp.length) {
 		memcpy(nsge, &tmp, sizeof(*nsge));
+		sk_msg_sg_copy_assign(msg_npl, j, msg_opl, tmp_i);
 		sk_msg_iter_var_next(j);
 		nsge = sk_msg_elem(msg_npl, j);
 	}
@@ -666,6 +669,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 	osge = sk_msg_elem(msg_opl, i);
 	while (osge->length) {
 		memcpy(nsge, osge, sizeof(*nsge));
+		sk_msg_sg_copy_assign(msg_npl, j, msg_opl, i);
 		sg_unmark_end(nsge);
 		sk_msg_iter_var_next(i);
 		sk_msg_iter_var_next(j);
-- 
2.53.0


^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2026-07-02 15:11 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-02  8:27 FAILED: patch "[PATCH] net: skmsg: preserve sg.copy across SG transforms" failed to apply to 5.15-stable tree gregkh
2026-07-02 15:11 ` [PATCH 5.15.y 1/2] skmsg: convert struct sk_msg_sg::copy to a bitmap Sasha Levin
2026-07-02 15:11   ` [PATCH 5.15.y 2/2] net: skmsg: preserve sg.copy across SG transforms Sasha Levin

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