[ Upstream commit f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 ]
syzkaller discovered the following crash: (kernel BUG)
[ 44.607039] ------------[ cut here ]------------
[ 44.607422] kernel BUG at mm/userfaultfd.c:2067!
[ 44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
[ 44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none)
[ 44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460
<snip other registers, drop unreliable trace>
[ 44.617726] Call Trace:
[ 44.617926] <TASK>
[ 44.619284] userfaultfd_release+0xef/0x1b0
[ 44.620976] __fput+0x3f9/0xb60
[ 44.621240] fput_close_sync+0x110/0x210
[ 44.622222] __x64_sys_close+0x8f/0x120
[ 44.622530] do_syscall_64+0x5b/0x2f0
[ 44.622840] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 44.623244] RIP: 0033:0x7f365bb3f227
Kernel panics because it detects UFFD inconsistency during
userfaultfd_release_all(). Specifically, a VMA which has a valid pointer
to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags.
The inconsistency is caused in ksm_madvise(): when user calls madvise()
with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode,
it accidentally clears all flags stored in the upper 32 bits of
vma->vm_flags.
Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and
int are 32-bit wide. This setup causes the following mishap during the &=
~VM_MERGEABLE assignment.
VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000.
After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then
promoted to unsigned long before the & operation. This promotion fills
upper 32 bits with leading 0s, as we're doing unsigned conversion (and
even for a signed conversion, this wouldn't help as the leading bit is 0).
& operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff
instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears
the upper 32-bits of its value.
Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the
BIT() macro.
Note: other VM_* flags are not affected: This only happens to the
VM_MERGEABLE flag, as the other VM_* flags are all constants of type int
and after ~ operation, they end up with leading 1 and are thus converted
to unsigned long with leading 1s.
Note 2:
After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is
no longer a kernel BUG, but a WARNING at the same place:
[ 45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067
but the root-cause (flag-drop) remains the same.
[akpm(a)linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel]
Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/
Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de
Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode")
Signed-off-by: Jakub Acs <acsjakub(a)amazon.de>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Acked-by: SeongJae Park <sj(a)kernel.org>
Tested-by: Alice Ryhl <aliceryhl(a)google.com>
Tested-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com>
Cc: Xu Xin <xu.xin16(a)zte.com.cn>
Cc: Chengming Zhou <chengming.zhou(a)linux.dev>
Cc: Peter Xu <peterx(a)redhat.com>
Cc: Axel Rasmussen <axelrasmussen(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
[ acsjakub: drop rust-compatibility change (no rust in 5.4) ]
Signed-off-by: Jakub Acs <acsjakub(a)amazon.de>
---
Why sending to stable version from before "fixes"?
In the original patch, I set fixes tag to the change that allows the
panic to manifest, not to the one that is real root-cause of the
problem.
The change that introduced the root-cause of the problem is:
f8af4da3b4c1 ("ksm: the mm interface to ksm"), as pointed out by
Vlastimil in [1].
Hence, as the older kernels can be affected by the flag-drop as well,
backport to older kernels.
[1]: https://lore.kernel.org/all/13c7242e-3a40-469b-9e99-8a65a21449bb@suse.cz/
include/linux/mm.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 57cba6e4fdcd..be8c793233d3 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -293,7 +293,7 @@ extern unsigned int kobjsize(const void *objp);
#define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */
#define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */
#define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */
-#define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */
+#define VM_MERGEABLE BIT(31) /* KSM may merge identical pages */
#ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
#define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */
--
2.47.3
Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Christof Hellmis
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597
commit 44e8241c51f762aafa50ed116da68fd6ecdcc954 upstream.
On big endian arm kernels, the arm optimized Curve25519 code produces
incorrect outputs and fails the Curve25519 test. This has been true
ever since this code was added.
It seems that hardly anyone (or even no one?) actually uses big endian
arm kernels. But as long as they're ostensibly supported, we should
disable this code on them so that it's not accidentally used.
Note: for future-proofing, use !CPU_BIG_ENDIAN instead of
CPU_LITTLE_ENDIAN. Both of these are arch-specific options that could
get removed in the future if big endian support gets dropped.
Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation")
Cc: stable(a)vger.kernel.org
Acked-by: Ard Biesheuvel <ardb(a)kernel.org>
Link: https://lore.kernel.org/r/20251104054906.716914-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers(a)kernel.org>
---
arch/arm/crypto/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
index c46c05548080..c5d676e7f16b 100644
--- a/arch/arm/crypto/Kconfig
+++ b/arch/arm/crypto/Kconfig
@@ -145,10 +145,10 @@ config CRYPTO_NHPOLY1305_NEON
depends on KERNEL_MODE_NEON
select CRYPTO_NHPOLY1305
config CRYPTO_CURVE25519_NEON
tristate "NEON accelerated Curve25519 scalar multiplication library"
- depends on KERNEL_MODE_NEON
+ depends on KERNEL_MODE_NEON && !CPU_BIG_ENDIAN
select CRYPTO_LIB_CURVE25519_GENERIC
select CRYPTO_ARCH_HAVE_LIB_CURVE25519
endif
base-commit: df70e44fa05b01476a78d0f6a210354784ff0992
--
2.51.2
[ Upstream commit f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 ]
syzkaller discovered the following crash: (kernel BUG)
[ 44.607039] ------------[ cut here ]------------
[ 44.607422] kernel BUG at mm/userfaultfd.c:2067!
[ 44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
[ 44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none)
[ 44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460
<snip other registers, drop unreliable trace>
[ 44.617726] Call Trace:
[ 44.617926] <TASK>
[ 44.619284] userfaultfd_release+0xef/0x1b0
[ 44.620976] __fput+0x3f9/0xb60
[ 44.621240] fput_close_sync+0x110/0x210
[ 44.622222] __x64_sys_close+0x8f/0x120
[ 44.622530] do_syscall_64+0x5b/0x2f0
[ 44.622840] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 44.623244] RIP: 0033:0x7f365bb3f227
Kernel panics because it detects UFFD inconsistency during
userfaultfd_release_all(). Specifically, a VMA which has a valid pointer
to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags.
The inconsistency is caused in ksm_madvise(): when user calls madvise()
with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode,
it accidentally clears all flags stored in the upper 32 bits of
vma->vm_flags.
Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and
int are 32-bit wide. This setup causes the following mishap during the &=
~VM_MERGEABLE assignment.
VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000.
After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then
promoted to unsigned long before the & operation. This promotion fills
upper 32 bits with leading 0s, as we're doing unsigned conversion (and
even for a signed conversion, this wouldn't help as the leading bit is 0).
& operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff
instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears
the upper 32-bits of its value.
Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the
BIT() macro.
Note: other VM_* flags are not affected: This only happens to the
VM_MERGEABLE flag, as the other VM_* flags are all constants of type int
and after ~ operation, they end up with leading 1 and are thus converted
to unsigned long with leading 1s.
Note 2:
After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is
no longer a kernel BUG, but a WARNING at the same place:
[ 45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067
but the root-cause (flag-drop) remains the same.
[akpm(a)linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel]
Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/
Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de
Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode")
Signed-off-by: Jakub Acs <acsjakub(a)amazon.de>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Acked-by: SeongJae Park <sj(a)kernel.org>
Tested-by: Alice Ryhl <aliceryhl(a)google.com>
Tested-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com>
Cc: Xu Xin <xu.xin16(a)zte.com.cn>
Cc: Chengming Zhou <chengming.zhou(a)linux.dev>
Cc: Peter Xu <peterx(a)redhat.com>
Cc: Axel Rasmussen <axelrasmussen(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
[ acsjakub: drop rust-compatibility change (no rust in 5.10) ]
Signed-off-by: Jakub Acs <acsjakub(a)amazon.de>
---
Why sending to stable version from before "fixes"?
In the original patch, I set fixes tag to the change that allows the
panic to manifest, not to the one that is real root-cause of the
problem.
The change that introduced the root-cause of the problem is:
f8af4da3b4c1 ("ksm: the mm interface to ksm"), as pointed out by
Vlastimil in [1].
Hence, as the older kernels can be affected by the flag-drop as well,
backport to older kernels.
[1]: https://lore.kernel.org/all/13c7242e-3a40-469b-9e99-8a65a21449bb@suse.cz/
include/linux/mm.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e168d87d6f2e..4787d39bbad4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -296,7 +296,7 @@ extern unsigned int kobjsize(const void *objp);
#define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */
#define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */
#define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */
-#define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */
+#define VM_MERGEABLE BIT(31) /* KSM may merge identical pages */
#ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
#define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */
--
2.47.3
Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Christof Hellmis
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597
commit 44e8241c51f762aafa50ed116da68fd6ecdcc954 upstream.
On big endian arm kernels, the arm optimized Curve25519 code produces
incorrect outputs and fails the Curve25519 test. This has been true
ever since this code was added.
It seems that hardly anyone (or even no one?) actually uses big endian
arm kernels. But as long as they're ostensibly supported, we should
disable this code on them so that it's not accidentally used.
Note: for future-proofing, use !CPU_BIG_ENDIAN instead of
CPU_LITTLE_ENDIAN. Both of these are arch-specific options that could
get removed in the future if big endian support gets dropped.
Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation")
Cc: stable(a)vger.kernel.org
Acked-by: Ard Biesheuvel <ardb(a)kernel.org>
Link: https://lore.kernel.org/r/20251104054906.716914-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers(a)kernel.org>
---
arch/arm/crypto/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
index 149a5bd6b88c..d3d318df0e38 100644
--- a/arch/arm/crypto/Kconfig
+++ b/arch/arm/crypto/Kconfig
@@ -164,10 +164,10 @@ config CRYPTO_NHPOLY1305_NEON
depends on KERNEL_MODE_NEON
select CRYPTO_NHPOLY1305
config CRYPTO_CURVE25519_NEON
tristate "NEON accelerated Curve25519 scalar multiplication library"
- depends on KERNEL_MODE_NEON
+ depends on KERNEL_MODE_NEON && !CPU_BIG_ENDIAN
select CRYPTO_LIB_CURVE25519_GENERIC
select CRYPTO_ARCH_HAVE_LIB_CURVE25519
endif
base-commit: cc5ec87693063acebb60f587e8a019ba9b94ae0e
--
2.51.2
[ Upstream commit f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 ]
syzkaller discovered the following crash: (kernel BUG)
[ 44.607039] ------------[ cut here ]------------
[ 44.607422] kernel BUG at mm/userfaultfd.c:2067!
[ 44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
[ 44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none)
[ 44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460
<snip other registers, drop unreliable trace>
[ 44.617726] Call Trace:
[ 44.617926] <TASK>
[ 44.619284] userfaultfd_release+0xef/0x1b0
[ 44.620976] __fput+0x3f9/0xb60
[ 44.621240] fput_close_sync+0x110/0x210
[ 44.622222] __x64_sys_close+0x8f/0x120
[ 44.622530] do_syscall_64+0x5b/0x2f0
[ 44.622840] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 44.623244] RIP: 0033:0x7f365bb3f227
Kernel panics because it detects UFFD inconsistency during
userfaultfd_release_all(). Specifically, a VMA which has a valid pointer
to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags.
The inconsistency is caused in ksm_madvise(): when user calls madvise()
with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode,
it accidentally clears all flags stored in the upper 32 bits of
vma->vm_flags.
Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and
int are 32-bit wide. This setup causes the following mishap during the &=
~VM_MERGEABLE assignment.
VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000.
After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then
promoted to unsigned long before the & operation. This promotion fills
upper 32 bits with leading 0s, as we're doing unsigned conversion (and
even for a signed conversion, this wouldn't help as the leading bit is 0).
& operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff
instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears
the upper 32-bits of its value.
Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the
BIT() macro.
Note: other VM_* flags are not affected: This only happens to the
VM_MERGEABLE flag, as the other VM_* flags are all constants of type int
and after ~ operation, they end up with leading 1 and are thus converted
to unsigned long with leading 1s.
Note 2:
After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is
no longer a kernel BUG, but a WARNING at the same place:
[ 45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067
but the root-cause (flag-drop) remains the same.
[akpm(a)linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel]
Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/
Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de
Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode")
Signed-off-by: Jakub Acs <acsjakub(a)amazon.de>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Acked-by: SeongJae Park <sj(a)kernel.org>
Tested-by: Alice Ryhl <aliceryhl(a)google.com>
Tested-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com>
Cc: Xu Xin <xu.xin16(a)zte.com.cn>
Cc: Chengming Zhou <chengming.zhou(a)linux.dev>
Cc: Peter Xu <peterx(a)redhat.com>
Cc: Axel Rasmussen <axelrasmussen(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
[ acsjakub: drop rust-compatibility change (no rust in 5.15) ]
Signed-off-by: Jakub Acs <acsjakub(a)amazon.de>
---
Why sending to stable version from before "fixes"?
In the original patch, I set fixes tag to the change that allows the
panic to manifest, not to the one that is real root-cause of the
problem.
The change that introduced the root-cause of the problem is:
f8af4da3b4c1 ("ksm: the mm interface to ksm"), as pointed out by
Vlastimil in [1].
Hence, as the older kernels can be affected by the flag-drop as well,
backport to older kernels.
[1]: https://lore.kernel.org/all/13c7242e-3a40-469b-9e99-8a65a21449bb@suse.cz/
include/linux/mm.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3598925561b1..071dd864a7b2 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -310,7 +310,7 @@ extern unsigned int kobjsize(const void *objp);
#define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */
#define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */
#define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */
-#define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */
+#define VM_MERGEABLE BIT(31) /* KSM may merge identical pages */
#ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
#define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */
--
2.47.3
Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Christof Hellmis
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597
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(a)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 e84cb860ac3ce67ec6ecc364433fd5b412c448bc
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025102646-unwary-premises-4a2c@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e84cb860ac3ce67ec6ecc364433fd5b412c448bc Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
Date: Mon, 20 Oct 2025 22:53:26 +0200
Subject: [PATCH] mptcp: pm: in-kernel: C-flag: handle late ADD_ADDR
The special C-flag case expects the ADD_ADDR to be received when
switching to 'fully-established'. But for various reasons, the ADD_ADDR
could be sent after the "4th ACK", and the special case doesn't work.
On NIPA, the new test validating this special case for the C-flag failed
a few times, e.g.
102 default limits, server deny join id 0
syn rx [FAIL] got 0 JOIN[s] syn rx expected 2
Server ns stats
(...)
MPTcpExtAddAddrTx 1
MPTcpExtEchoAdd 1
Client ns stats
(...)
MPTcpExtAddAddr 1
MPTcpExtEchoAddTx 1
synack rx [FAIL] got 0 JOIN[s] synack rx expected 2
ack rx [FAIL] got 0 JOIN[s] ack rx expected 2
join Rx [FAIL] see above
syn tx [FAIL] got 0 JOIN[s] syn tx expected 2
join Tx [FAIL] see above
I had a suspicion about what the issue could be: the ADD_ADDR might have
been received after the switch to the 'fully-established' state. The
issue was not easy to reproduce. The packet capture shown that the
ADD_ADDR can indeed be sent with a delay, and the client would not try
to establish subflows to it as expected.
A simple fix is not to mark the endpoints as 'used' in the C-flag case,
when looking at creating subflows to the remote initial IP address and
port. In this case, there is no need to try.
Note: newly added fullmesh endpoints will still continue to be used as
expected, thanks to the conditions behind mptcp_pm_add_addr_c_flag_case.
Fixes: 4b1ff850e0c1 ("mptcp: pm: in-kernel: usable client side with C-flag")
Cc: stable(a)vger.kernel.org
Reviewed-by: Geliang Tang <geliang(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20251020-net-mptcp-c-flag-late-add-addr-v1-1-82070…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index e0f44dc232aa..2ae95476dba3 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -370,6 +370,10 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
}
subflow:
+ /* No need to try establishing subflows to remote id0 if not allowed */
+ if (mptcp_pm_add_addr_c_flag_case(msk))
+ goto exit;
+
/* check if should create a new subflow */
while (msk->pm.local_addr_used < endp_subflow_max &&
msk->pm.extra_subflows < limit_extra_subflows) {
@@ -401,6 +405,8 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
__mptcp_subflow_connect(sk, &local, &addrs[i]);
spin_lock_bh(&msk->pm.lock);
}
+
+exit:
mptcp_pm_nl_check_work_pending(msk);
}
Changes in v2:
- Add also resets
- Drop cc-stable tag in the last patch
- Link to v1: https://patch.msgid.link/20251029-dt-bindings-pci-qcom-fixes-power-domains-…
Recent binding changes forgot to make power-domains and resets required.
I am not updating SC8180xp because it will be fixed other way in my next
patchset.
Best regards,
Krzysztof
---
Krzysztof Kozlowski (9):
dt-bindings: PCI: qcom,pcie-sa8775p: Add missing required power-domains and resets
dt-bindings: PCI: qcom,pcie-sc7280: Add missing required power-domains and resets
dt-bindings: PCI: qcom,pcie-sc8280xp: Add missing required power-domains and resets
dt-bindings: PCI: qcom,pcie-sm8150: Add missing required power-domains and resets
dt-bindings: PCI: qcom,pcie-sm8250: Add missing required power-domains and resets
dt-bindings: PCI: qcom,pcie-sm8350: Add missing required power-domains and resets
dt-bindings: PCI: qcom,pcie-sm8450: Add missing required power-domains and resets
dt-bindings: PCI: qcom,pcie-sm8550: Add missing required power-domains and resets
dt-bindings: PCI: qcom,pcie-x1e80100: Add missing required power-domains and resets
Documentation/devicetree/bindings/pci/qcom,pcie-sa8775p.yaml | 3 +++
Documentation/devicetree/bindings/pci/qcom,pcie-sc7280.yaml | 5 +++++
Documentation/devicetree/bindings/pci/qcom,pcie-sc8280xp.yaml | 3 +++
Documentation/devicetree/bindings/pci/qcom,pcie-sm8150.yaml | 5 +++++
Documentation/devicetree/bindings/pci/qcom,pcie-sm8250.yaml | 5 +++++
Documentation/devicetree/bindings/pci/qcom,pcie-sm8350.yaml | 5 +++++
Documentation/devicetree/bindings/pci/qcom,pcie-sm8450.yaml | 5 +++++
Documentation/devicetree/bindings/pci/qcom,pcie-sm8550.yaml | 5 +++++
Documentation/devicetree/bindings/pci/qcom,pcie-x1e80100.yaml | 5 +++++
9 files changed, 41 insertions(+)
---
base-commit: 326bbf6e2b1ce8d1e6166cce2ca414aa241c382f
change-id: 20251029-dt-bindings-pci-qcom-fixes-power-domains-36a669b2e252
Best regards,
--
Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org>