GHSA-HR53-GF94-W7MP
Vulnerability from github – Published: 2026-05-06 12:30 – Updated: 2026-05-08 15:31In the Linux kernel, the following vulnerability has been resolved:
xfrm6: fix uninitialized saddr in xfrm6_get_saddr()
xfrm6_get_saddr() does not check the return value of ipv6_dev_get_saddr(). When ipv6_dev_get_saddr() fails to find a suitable source address (returns -EADDRNOTAVAIL), saddr->in6 is left uninitialized, but xfrm6_get_saddr() still returns 0 (success).
This causes the caller xfrm_tmpl_resolve_one() to use the uninitialized address in xfrm_state_find(), triggering KMSAN warning:
===================================================== BUG: KMSAN: uninit-value in xfrm_state_find+0x2424/0xa940 xfrm_state_find+0x2424/0xa940 xfrm_resolve_and_create_bundle+0x906/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 xfrm_lookup_route+0x63/0x2b0 ip_route_output_flow+0x1ce/0x270 udp_sendmsg+0x2ce1/0x3400 inet_sendmsg+0x1ef/0x2a0 __sock_sendmsg+0x278/0x3d0 __sys_sendto+0x593/0x720 __x64_sys_sendto+0x130/0x200 x64_sys_call+0x332b/0x3e70 do_syscall_64+0xd3/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f
Local variable tmp.i.i created at: xfrm_resolve_and_create_bundle+0x3e3/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 =====================================================
Fix by checking the return value of ipv6_dev_get_saddr() and propagating the error.
{
"affected": [],
"aliases": [
"CVE-2026-43139"
],
"database_specific": {
"cwe_ids": [
"CWE-908"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-06T12:16:31Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm6: fix uninitialized saddr in xfrm6_get_saddr()\n\nxfrm6_get_saddr() does not check the return value of\nipv6_dev_get_saddr(). When ipv6_dev_get_saddr() fails to find a suitable\nsource address (returns -EADDRNOTAVAIL), saddr-\u003ein6 is left\nuninitialized, but xfrm6_get_saddr() still returns 0 (success).\n\nThis causes the caller xfrm_tmpl_resolve_one() to use the uninitialized\naddress in xfrm_state_find(), triggering KMSAN warning:\n\n=====================================================\nBUG: KMSAN: uninit-value in xfrm_state_find+0x2424/0xa940\n xfrm_state_find+0x2424/0xa940\n xfrm_resolve_and_create_bundle+0x906/0x5a20\n xfrm_lookup_with_ifid+0xcc0/0x3770\n xfrm_lookup_route+0x63/0x2b0\n ip_route_output_flow+0x1ce/0x270\n udp_sendmsg+0x2ce1/0x3400\n inet_sendmsg+0x1ef/0x2a0\n __sock_sendmsg+0x278/0x3d0\n __sys_sendto+0x593/0x720\n __x64_sys_sendto+0x130/0x200\n x64_sys_call+0x332b/0x3e70\n do_syscall_64+0xd3/0xf80\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nLocal variable tmp.i.i created at:\n xfrm_resolve_and_create_bundle+0x3e3/0x5a20\n xfrm_lookup_with_ifid+0xcc0/0x3770\n=====================================================\n\nFix by checking the return value of ipv6_dev_get_saddr() and propagating\nthe error.",
"id": "GHSA-hr53-gf94-w7mp",
"modified": "2026-05-08T15:31:16Z",
"published": "2026-05-06T12:30:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43139"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1799d8abeabc68ec05679292aaf6cba93b343c05"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3dcd1664ac15eee6a690daec7c4ffc59190406f7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4f28141786e1fe884ce42a5197ba9beed540f0ea"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6535867673bf301d52aa00593a4d1d18cc3922fa"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/719918fc88df6da023dfff370cd965151a5afd7f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c7221e7bd8fc2ef38a0b27be580d9d202281306b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dc0abce055134cb83b0d981d31ceb20dda419787"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/eb2ee15290af14c60b45cf2b73f5687d1d077d9b"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
"type": "CVSS_V3"
}
]
}
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