<?xml version="1.0" encoding="UTF-8"?>
<cvrfdoc xmlns="http://www.icasi.org/CVRF/schema/cvrf/1.1" xmlns:cvrf="http://www.icasi.org/CVRF/schema/cvrf/1.1">
	<DocumentTitle xml:lang="en">An update for kernel is now available for openEuler-20.03-LTS-SP4</DocumentTitle>
	<DocumentType>Security Advisory</DocumentType>
	<DocumentPublisher Type="Vendor">
		<ContactDetails>openeuler-release@openeuler.org</ContactDetails>
		<IssuingAuthority>openEuler release SIG</IssuingAuthority>
	</DocumentPublisher>
	<DocumentTracking>
		<Identification>
			<ID>openEuler-HotPatchSA-2024-1032</ID>
		</Identification>
		<Status>Final</Status>
		<Version>1.0</Version>
		<RevisionHistory>
			<Revision>
				<Number>1.0</Number>
				<Date>2024-09-20</Date>
				<Description>Initial</Description>
			</Revision>
		</RevisionHistory>
		<InitialReleaseDate>2024-09-20</InitialReleaseDate>
		<CurrentReleaseDate>2024-09-20</CurrentReleaseDate>
		<Generator>
			<Engine>openEuler HotPatchSA Tool V1.0</Engine>
			<Date>2024-09-20</Date>
		</Generator>
	</DocumentTracking>
	<DocumentNotes>
		<Note Title="Synopsis" Type="General" Ordinal="1" xml:lang="en">kernel security update</Note>
		<Note Title="Summary" Type="General" Ordinal="2" xml:lang="en">An update for kernel is now available for openEuler-20.03-LTS-SP4</Note>
		<Note Title="Description" Type="General" Ordinal="3" xml:lang="en">The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().

Anderson Nascimento reported a use-after-free splat in tcp_twsk_unique()
with nice analysis.

Since commit ec94c2696f0b (&quot;tcp/dccp: avoid one atomic operation for
timewait hashdance&quot;), inet_twsk_hashdance() sets TIME-WAIT socket&apos;s
sk_refcnt after putting it into ehash and releasing the bucket lock.

Thus, there is a small race window where other threads could try to
reuse the port during connect() and call sock_hold() in tcp_twsk_unique()
for the TIME-WAIT socket with zero refcnt.

If that happens, the refcnt taken by tcp_twsk_unique() is overwritten
and sock_put() will cause underflow, triggering a real use-after-free
somewhere else.

To avoid the use-after-free, we need to use refcount_inc_not_zero() in
tcp_twsk_unique() and give up on reusing the port if it returns false.

[0]:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 1039313 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110
CPU: 0 PID: 1039313 Comm: trigger Not tainted 6.8.6-200.fc39.x86_64 #1
Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.21805430.B64.2305221830 05/22/2023
RIP: 0010:refcount_warn_saturate+0xe5/0x110
Code: 42 8e ff 0f 0b c3 cc cc cc cc 80 3d aa 13 ea 01 00 0f 85 5e ff ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff &lt;0f&gt; 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 01 01 e8
RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 0000000000000027
RDX: ffff88807be218c8 RSI: 0000000000000001 RDI: ffff88807be218c0
RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0
R10: ffffc90006b439e8 R11: 0000000000000003 R12: ffff8880029ede84
R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0
FS:  00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0
PKRU: 55555554
Call Trace:
 &lt;TASK&gt;
 ? refcount_warn_saturate+0xe5/0x110
 ? __warn+0x81/0x130
 ? refcount_warn_saturate+0xe5/0x110
 ? report_bug+0x171/0x1a0
 ? refcount_warn_saturate+0xe5/0x110
 ? handle_bug+0x3c/0x80
 ? exc_invalid_op+0x17/0x70
 ? asm_exc_invalid_op+0x1a/0x20
 ? refcount_warn_saturate+0xe5/0x110
 tcp_twsk_unique+0x186/0x190
 __inet_check_established+0x176/0x2d0
 __inet_hash_connect+0x74/0x7d0
 ? __pfx___inet_check_established+0x10/0x10
 tcp_v4_connect+0x278/0x530
 __inet_stream_connect+0x10f/0x3d0
 inet_stream_connect+0x3a/0x60
 __sys_connect+0xa8/0xd0
 __x64_sys_connect+0x18/0x20
 do_syscall_64+0x83/0x170
 entry_SYSCALL_64_after_hwframe+0x78/0x80
RIP: 0033:0x7f62c11a885d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 8b 0d a3 45 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000020ccb004 RCX: 00007f62c11a885d
RDX: 0000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003
RBP: 00007f62c1091e90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0
R13: ffffffffffffff88 R14: 0000000000000000 R15: 00007ffe237885b0
 &lt;/TASK&gt;(CVE-2024-36904)</Note>
		<Note Title="Topic" Type="General" Ordinal="4" xml:lang="en">An update for kernel is now available for openEuler-20.03-LTS-SP4.

openEuler Security has rated this update as having a security impact of high. A Common Vunlnerability Scoring System(CVSS)base score,which gives a detailed severity rating, is available for each vulnerability from the CVElink(s) in the References section.</Note>
		<Note Title="Severity" Type="General" Ordinal="5" xml:lang="en">High</Note>
		<Note Title="Affected Component" Type="General" Ordinal="6" xml:lang="en">kernel</Note>
	</DocumentNotes>
	<DocumentReferences>
		<Reference Type="Self">
			<URL>https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-HotPatchSA-2024-1032</URL>
		</Reference>
		<Reference Type="openEuler CVE">
			<URL>https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2024-36904</URL>
		</Reference>
		<Reference Type="Other">
			<URL>https://nvd.nist.gov/vuln/detail/CVE-2024-36904</URL>
		</Reference>
	</DocumentReferences>
	<HotPatchTree xmlns="http://www.icasi.org/CVRF/schema/prod/1.1">
		<Branch Type="Product Name" Name="openEuler">
			<FullProductName ProductID="openEuler-20.03-LTS-SP4" CPE="cpe:/a:openEuler:openEuler:20.03-LTS-SP4">openEuler-20.03-LTS-SP4</FullProductName>
		</Branch>
		<Branch Type="Package Arch" Name="src">
			<FullProductName ProductID="kernel-4.19.90-2312.1.0.0255.oe2003sp4-ACC-1-5" CPE="cpe:/a:openEuler:openEuler:20.03-LTS-SP4">kernel-4.19.90-2312.1.0.0255.oe2003sp4-ACC-1-5.src.rpm</FullProductName>
		</Branch>
		<Branch Type="Package Arch" Name="x86_64">
			<FullProductName ProductID="patch-kernel-4.19.90-2312.1.0.0255.oe2003sp4-ACC-1-5" CPE="cpe:/a:openEuler:openEuler:20.03-LTS-SP4">patch-kernel-4.19.90-2312.1.0.0255.oe2003sp4-ACC-1-5.x86_64.rpm</FullProductName>
		</Branch>
		<Branch Type="Package Arch" Name="aarch64">
			<FullProductName ProductID="patch-kernel-4.19.90-2312.1.0.0255.oe2003sp4-ACC-1-5" CPE="cpe:/a:openEuler:openEuler:20.03-LTS-SP4">patch-kernel-4.19.90-2312.1.0.0255.oe2003sp4-ACC-1-5.aarch64.rpm</FullProductName>
		</Branch>
	</HotPatchTree>
	<Vulnerability Ordinal="1" xmlns="http://www.icasi.org/CVRF/schema/cvrf/1.1">
		<Notes>
			<Note Title="Vulnerability Description" Type="General" Ordinal="1" xml:lang="en">In the Linux kernel, the following vulnerability has been resolved:

tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().

Anderson Nascimento reported a use-after-free splat in tcp_twsk_unique()
with nice analysis.

Since commit ec94c2696f0b (&quot;tcp/dccp: avoid one atomic operation for
timewait hashdance&quot;), inet_twsk_hashdance() sets TIME-WAIT socket&apos;s
sk_refcnt after putting it into ehash and releasing the bucket lock.

Thus, there is a small race window where other threads could try to
reuse the port during connect() and call sock_hold() in tcp_twsk_unique()
for the TIME-WAIT socket with zero refcnt.

If that happens, the refcnt taken by tcp_twsk_unique() is overwritten
and sock_put() will cause underflow, triggering a real use-after-free
somewhere else.

To avoid the use-after-free, we need to use refcount_inc_not_zero() in
tcp_twsk_unique() and give up on reusing the port if it returns false.

[0]:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 1039313 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110
CPU: 0 PID: 1039313 Comm: trigger Not tainted 6.8.6-200.fc39.x86_64 #1
Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.21805430.B64.2305221830 05/22/2023
RIP: 0010:refcount_warn_saturate+0xe5/0x110
Code: 42 8e ff 0f 0b c3 cc cc cc cc 80 3d aa 13 ea 01 00 0f 85 5e ff ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff &lt;0f&gt; 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 01 01 e8
RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 0000000000000027
RDX: ffff88807be218c8 RSI: 0000000000000001 RDI: ffff88807be218c0
RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0
R10: ffffc90006b439e8 R11: 0000000000000003 R12: ffff8880029ede84
R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0
FS:  00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0
PKRU: 55555554
Call Trace:
 &lt;TASK&gt;
 ? refcount_warn_saturate+0xe5/0x110
 ? __warn+0x81/0x130
 ? refcount_warn_saturate+0xe5/0x110
 ? report_bug+0x171/0x1a0
 ? refcount_warn_saturate+0xe5/0x110
 ? handle_bug+0x3c/0x80
 ? exc_invalid_op+0x17/0x70
 ? asm_exc_invalid_op+0x1a/0x20
 ? refcount_warn_saturate+0xe5/0x110
 tcp_twsk_unique+0x186/0x190
 __inet_check_established+0x176/0x2d0
 __inet_hash_connect+0x74/0x7d0
 ? __pfx___inet_check_established+0x10/0x10
 tcp_v4_connect+0x278/0x530
 __inet_stream_connect+0x10f/0x3d0
 inet_stream_connect+0x3a/0x60
 __sys_connect+0xa8/0xd0
 __x64_sys_connect+0x18/0x20
 do_syscall_64+0x83/0x170
 entry_SYSCALL_64_after_hwframe+0x78/0x80
RIP: 0033:0x7f62c11a885d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 8b 0d a3 45 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000020ccb004 RCX: 00007f62c11a885d
RDX: 0000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003
RBP: 00007f62c1091e90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0
R13: ffffffffffffff88 R14: 0000000000000000 R15: 00007ffe237885b0
 &lt;/TASK&gt;</Note>
		</Notes>
		<ReleaseDate>2024-09-20</ReleaseDate>
		<CVE>CVE-2024-36904</CVE>
		<ProductStatuses>
			<Status Type="Fixed">
				<ProductID>openEuler-20.03-LTS-SP4</ProductID>
			</Status>
		</ProductStatuses>
		<Threats>
			<Threat Type="Impact">
				<Description>High</Description>
			</Threat>
		</Threats>
		<CVSSScoreSets>
			<ScoreSet>
				<BaseScore>7.0</BaseScore>
				<Vector>AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H</Vector>
			</ScoreSet>
		</CVSSScoreSets>
		<Remediations>
			<Remediation Type="Vendor Fix">
				<Description>kernel security update</Description>
				<DATE>2024-09-20</DATE>
				<URL>https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-HotPatchSA-2024-1032</URL>
			</Remediation>
		</Remediations>
	</Vulnerability>
</cvrfdoc>