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FAILED: patch "[PATCH] xfrm: ah: account for ESN high bits in async callbacks" failed to apply to 6.6-stable tree

PATCH New [email protected] 2 participants 4 messages May 12 – May 13

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#0 lore raw

The patch below does not apply to the 6.6-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 <[email protected]>.

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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x ec54093e6a8f87e800bb6aa15eb7fc1e33faa524
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026051234-stabilize-delicious-029c@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From ec54093e6a8f87e800bb6aa15eb7fc1e33faa524 Mon Sep 17 00:00:00 2001
From: Michael Bommarito <[email protected]>
Date: Sun, 19 Apr 2026 18:35:42 -0400
Subject: [PATCH] xfrm: ah: account for ESN high bits in async callbacks

AH allocates its temporary auth/ICV layout differently when ESN is enabled:
the async ahash setup appends a 4-byte seqhi slot before the ICV or auth_data area, but the async completion callbacks still reconstruct the temporary layout as if seqhi were absent.

With an async AH implementation selected, that makes AH copy or compare the wrong bytes on both the IPv4 and IPv6 paths. In UML repro on IPv4 AH with ESN and forced async hmac(sha1), ping fails with 100% packet loss, and the callback logs show the pre-fix drift:

ah4 output_done: esn=1 err=0 icv_off=20 expected_off=24
ah4 input_done: esn=1 auth_off=20 expected_auth_off=24 icv_off=32 expected_icv_off=36

Reconstruct the callback-side layout the same way the setup path built it by skipping the ESN seqhi slot before locating the saved auth_data or ICV. Per RFC 4302, the ESN high-order 32 bits participate in the AH ICV computation, so the async callbacks must account for the seqhi slot.

Post-fix, the same IPv4 AH+ESN+forced-async-hmac(sha1) UML repro shows the corrected offset (ah4 output_done: esn=1 err=0 icv_off=24 expected_off=24) and ping succeeds; net/ipv4/ah4.o and net/ipv6/ah6.o build clean at W=1. IPv6 AH+ESN was not exercised at runtime, and the change has not been tested against a real async hardware AH engine.

Fixes d4d573d0334d ("{IPv4,xfrm} Add ESN support for AH egress part")
Fixes d8b2a8600b0e ("{IPv4,xfrm} Add ESN support for AH ingress part")
Fixes 26dd70c3fad3 ("{IPv6,xfrm} Add ESN support for AH egress part")
Fixes 8d6da6f32557 ("{IPv6,xfrm} Add ESN support for AH ingress part")
Assisted-by Codex:gpt-5-4
Assisted-by Claude:claude-opus-4-7
net/ipv4/ah4.c +12 -2
index 5fb812443a08..4366cbac3f06 100644
@@ -124,9 +124,14 @@ static void ah_output_done(void *data, int err)
 	struct iphdr *top_iph = ip_hdr(skb);
 	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
 	int ihl = ip_hdrlen(skb);
+	int seqhi_len = 0;
+	__be32 *seqhi;
 
+	if (x->props.flags & XFRM_STATE_ESN)
+		seqhi_len = sizeof(*seqhi);
 	iph = AH_SKB_CB(skb)->tmp;
-	icv = ah_tmp_icv(iph, ihl);
+	seqhi = (__be32 *)((char *)iph + ihl);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
 
 	top_iph->tos = iph->tos;
@@ -270,12 +275,17 @@ static void ah_input_done(void *data, int err)
 	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
 	int ihl = ip_hdrlen(skb);
 	int ah_hlen = (ah->hdrlen + 2) << 2;
+	int seqhi_len = 0;
+	__be32 *seqhi;
 
 	if (err)
 		goto out;
 
+	if (x->props.flags & XFRM_STATE_ESN)
+		seqhi_len = sizeof(*seqhi);
 	work_iph = AH_SKB_CB(skb)->tmp;
-	auth_data = ah_tmp_auth(work_iph, ihl);
+	seqhi = (__be32 *)((char *)work_iph + ihl);
+	auth_data = ah_tmp_auth(seqhi, seqhi_len);
 	icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
 
 	err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
net/ipv6/ah6.c +12 -2
index cb26beea4398..de1e68199a01 100644
@@ -317,14 +317,19 @@ static void ah6_output_done(void *data, int err)
 	struct ipv6hdr *top_iph = ipv6_hdr(skb);
 	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
 	struct tmp_ext *iph_ext;
+	int seqhi_len = 0;
+	__be32 *seqhi;
 
 	extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
 	if (extlen)
 		extlen += sizeof(*iph_ext);
 
+	if (x->props.flags & XFRM_STATE_ESN)
+		seqhi_len = sizeof(*seqhi);
 	iph_base = AH_SKB_CB(skb)->tmp;
 	iph_ext = ah_tmp_ext(iph_base);
-	icv = ah_tmp_icv(iph_ext, extlen);
+	seqhi = (__be32 *)((char *)iph_ext + extlen);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 
 	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
 	memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
@@ -471,13 +476,18 @@ static void ah6_input_done(void *data, int err)
 	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
 	int hdr_len = skb_network_header_len(skb);
 	int ah_hlen = ipv6_authlen(ah);
+	int seqhi_len = 0;
+	__be32 *seqhi;
 
 	if (err)
 		goto out;
 
+	if (x->props.flags & XFRM_STATE_ESN)
+		seqhi_len = sizeof(*seqhi);
 	work_iph = AH_SKB_CB(skb)->tmp;
 	auth_data = ah_tmp_auth(work_iph, hdr_len);
-	icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
+	seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 
 	err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
 	if (err)
maintainer
#1 lore raw

PATCH 1/3 net: ipv4: stop checking crypto_ahash_alignmask

From: Eric Biggers <[email protected]>

[ Upstream commit e77f5dd701381cef35b9ea8b6dea6e62c8a7f9f3 ]

Now that the alignmask for ahash and shash algorithms is always 0, crypto_ahash_alignmask() always returns 0 and will be removed. In preparation for this, stop checking crypto_ahash_alignmask() in ah4.c.

Stable-dep-of: ec54093e6a8f ("xfrm: ah: account for ESN high bits in async callbacks")

---
 net/ipv4/ah4.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)
net/ipv4/ah4.c +7 -10
index 015c0f4ec5ba9..cf31fb266bc10 100644
@@ -27,9 +27,7 @@ static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
 {
 	unsigned int len;
 
-	len = size + crypto_ahash_digestsize(ahash) +
-	      (crypto_ahash_alignmask(ahash) &
-	       ~(crypto_tfm_ctx_alignment() - 1));
+	len = size + crypto_ahash_digestsize(ahash);
 
 	len = ALIGN(len, crypto_tfm_ctx_alignment());
 
@@ -46,10 +44,9 @@ static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset)
 	return tmp + offset;
 }
 
-static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
-			     unsigned int offset)
+static inline u8 *ah_tmp_icv(void *tmp, unsigned int offset)
 {
-	return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
+	return tmp + offset;
 }
 
 static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
@@ -129,7 +126,7 @@ static void ah_output_done(void *data, int err)
 	int ihl = ip_hdrlen(skb);
 
 	iph = AH_SKB_CB(skb)->tmp;
-	icv = ah_tmp_icv(ahp->ahash, iph, ihl);
+	icv = ah_tmp_icv(iph, ihl);
 	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
 
 	top_iph->tos = iph->tos;
@@ -182,7 +179,7 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
 	if (!iph)
 		goto out;
 	seqhi = (__be32 *)((char *)iph + ihl);
-	icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 	req = ah_tmp_req(ahash, icv);
 	sg = ah_req_sg(ahash, req);
 	seqhisg = sg + nfrags;
@@ -279,7 +276,7 @@ static void ah_input_done(void *data, int err)
 
 	work_iph = AH_SKB_CB(skb)->tmp;
 	auth_data = ah_tmp_auth(work_iph, ihl);
-	icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
+	icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
 
 	err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
 	if (err)
@@ -374,7 +371,7 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	seqhi = (__be32 *)((char *)work_iph + ihl);
 	auth_data = ah_tmp_auth(seqhi, seqhi_len);
-	icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len);
+	icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
 	req = ah_tmp_req(ahash, icv);
 	sg = ah_req_sg(ahash, req);
 	seqhisg = sg + nfrags;
Signature · 1 line
2.53.0
maintainer
#2 lore raw

PATCH 2/3 net: ipv6: stop checking crypto_ahash_alignmask

From: Eric Biggers <[email protected]>

[ Upstream commit 0a6bfaa0e695facb072f2fedfb55df37c4483b50 ]

Now that the alignmask for ahash and shash algorithms is always 0, crypto_ahash_alignmask() always returns 0 and will be removed. In preparation for this, stop checking crypto_ahash_alignmask() in ah6.c.

Stable-dep-of: ec54093e6a8f ("xfrm: ah: account for ESN high bits in async callbacks")

---
 net/ipv6/ah6.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)
net/ipv6/ah6.c +7 -10
index 5361e2107458f..1938d96e2c0fd 100644
@@ -79,9 +79,7 @@ static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
 {
 	unsigned int len;
 
-	len = size + crypto_ahash_digestsize(ahash) +
-	      (crypto_ahash_alignmask(ahash) &
-	       ~(crypto_tfm_ctx_alignment() - 1));
+	len = size + crypto_ahash_digestsize(ahash);
 
 	len = ALIGN(len, crypto_tfm_ctx_alignment());
 
@@ -103,10 +101,9 @@ static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset)
 	return tmp + offset;
 }
 
-static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
-			     unsigned int offset)
+static inline u8 *ah_tmp_icv(void *tmp, unsigned int offset)
 {
-	return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
+	return tmp + offset;
 }
 
 static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
@@ -327,7 +324,7 @@ static void ah6_output_done(void *data, int err)
 
 	iph_base = AH_SKB_CB(skb)->tmp;
 	iph_ext = ah_tmp_ext(iph_base);
-	icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen);
+	icv = ah_tmp_icv(iph_ext, extlen);
 
 	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
 	memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
@@ -384,7 +381,7 @@ static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
 
 	iph_ext = ah_tmp_ext(iph_base);
 	seqhi = (__be32 *)((char *)iph_ext + extlen);
-	icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 	req = ah_tmp_req(ahash, icv);
 	sg = ah_req_sg(ahash, req);
 	seqhisg = sg + nfrags;
@@ -480,7 +477,7 @@ static void ah6_input_done(void *data, int err)
 
 	work_iph = AH_SKB_CB(skb)->tmp;
 	auth_data = ah_tmp_auth(work_iph, hdr_len);
-	icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
+	icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
 
 	err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
 	if (err)
@@ -588,7 +585,7 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len);
 	seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);
-	icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 	req = ah_tmp_req(ahash, icv);
 	sg = ah_req_sg(ahash, req);
 	seqhisg = sg + nfrags;
Signature · 1 line
2.53.0
maintainer
#3 lore raw

PATCH 3/3 xfrm: ah: account for ESN high bits in async callbacks

In reply to Sasha Levin

From: Michael Bommarito <[email protected]>

[ Upstream commit ec54093e6a8f87e800bb6aa15eb7fc1e33faa524 ]

AH allocates its temporary auth/ICV layout differently when ESN is enabled:
the async ahash setup appends a 4-byte seqhi slot before the ICV or auth_data area, but the async completion callbacks still reconstruct the temporary layout as if seqhi were absent.

With an async AH implementation selected, that makes AH copy or compare the wrong bytes on both the IPv4 and IPv6 paths. In UML repro on IPv4 AH with ESN and forced async hmac(sha1), ping fails with 100% packet loss, and the callback logs show the pre-fix drift:

ah4 output_done: esn=1 err=0 icv_off=20 expected_off=24
ah4 input_done: esn=1 auth_off=20 expected_auth_off=24 icv_off=32 expected_icv_off=36

Reconstruct the callback-side layout the same way the setup path built it by skipping the ESN seqhi slot before locating the saved auth_data or ICV. Per RFC 4302, the ESN high-order 32 bits participate in the AH ICV computation, so the async callbacks must account for the seqhi slot.

Post-fix, the same IPv4 AH+ESN+forced-async-hmac(sha1) UML repro shows the corrected offset (ah4 output_done: esn=1 err=0 icv_off=24 expected_off=24) and ping succeeds; net/ipv4/ah4.o and net/ipv6/ah6.o build clean at W=1. IPv6 AH+ESN was not exercised at runtime, and the change has not been tested against a real async hardware AH engine.

Fixes d4d573d0334d ("{IPv4,xfrm} Add ESN support for AH egress part")
Fixes d8b2a8600b0e ("{IPv4,xfrm} Add ESN support for AH ingress part")
Fixes 26dd70c3fad3 ("{IPv6,xfrm} Add ESN support for AH egress part")
Fixes 8d6da6f32557 ("{IPv6,xfrm} Add ESN support for AH ingress part")
Assisted-by Codex:gpt-5-4
Assisted-by Claude:claude-opus-4-7
---
 net/ipv4/ah4.c | 14 ++++++++++++--
 net/ipv6/ah6.c | 14 ++++++++++++--
 2 files changed, 24 insertions(+), 4 deletions(-)
net/ipv4/ah4.c +12 -2
index cf31fb266bc10..9f00d251770d4 100644
@@ -124,9 +124,14 @@ static void ah_output_done(void *data, int err)
 	struct iphdr *top_iph = ip_hdr(skb);
 	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
 	int ihl = ip_hdrlen(skb);
+	int seqhi_len = 0;
+	__be32 *seqhi;
 
+	if (x->props.flags & XFRM_STATE_ESN)
+		seqhi_len = sizeof(*seqhi);
 	iph = AH_SKB_CB(skb)->tmp;
-	icv = ah_tmp_icv(iph, ihl);
+	seqhi = (__be32 *)((char *)iph + ihl);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
 
 	top_iph->tos = iph->tos;
@@ -270,12 +275,17 @@ static void ah_input_done(void *data, int err)
 	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
 	int ihl = ip_hdrlen(skb);
 	int ah_hlen = (ah->hdrlen + 2) << 2;
+	int seqhi_len = 0;
+	__be32 *seqhi;
 
 	if (err)
 		goto out;
 
+	if (x->props.flags & XFRM_STATE_ESN)
+		seqhi_len = sizeof(*seqhi);
 	work_iph = AH_SKB_CB(skb)->tmp;
-	auth_data = ah_tmp_auth(work_iph, ihl);
+	seqhi = (__be32 *)((char *)work_iph + ihl);
+	auth_data = ah_tmp_auth(seqhi, seqhi_len);
 	icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
 
 	err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
net/ipv6/ah6.c +12 -2
index 1938d96e2c0fd..c6f1ad058dd28 100644
@@ -317,14 +317,19 @@ static void ah6_output_done(void *data, int err)
 	struct ipv6hdr *top_iph = ipv6_hdr(skb);
 	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
 	struct tmp_ext *iph_ext;
+	int seqhi_len = 0;
+	__be32 *seqhi;
 
 	extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
 	if (extlen)
 		extlen += sizeof(*iph_ext);
 
+	if (x->props.flags & XFRM_STATE_ESN)
+		seqhi_len = sizeof(*seqhi);
 	iph_base = AH_SKB_CB(skb)->tmp;
 	iph_ext = ah_tmp_ext(iph_base);
-	icv = ah_tmp_icv(iph_ext, extlen);
+	seqhi = (__be32 *)((char *)iph_ext + extlen);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 
 	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
 	memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
@@ -471,13 +476,18 @@ static void ah6_input_done(void *data, int err)
 	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
 	int hdr_len = skb_network_header_len(skb);
 	int ah_hlen = ipv6_authlen(ah);
+	int seqhi_len = 0;
+	__be32 *seqhi;
 
 	if (err)
 		goto out;
 
+	if (x->props.flags & XFRM_STATE_ESN)
+		seqhi_len = sizeof(*seqhi);
 	work_iph = AH_SKB_CB(skb)->tmp;
 	auth_data = ah_tmp_auth(work_iph, hdr_len);
-	icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len);
+	seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);
+	icv = ah_tmp_icv(seqhi, seqhi_len);
 
 	err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
 	if (err)
Signature · 1 line
2.53.0