CVE-2023-52906 Affecting kernel-azure package, versions <5.14.21-150500.33.66.1
Threat Intelligence
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Test your applications- Snyk IDSNYK-SLES155-KERNELAZURE-7928508
- published11 Sept 2024
- disclosed10 Sept 2024
Introduced: 10 Sep 2024
CVE-2023-52906 (opens in a new tab)How to fix?
Upgrade SLES:15.5 kernel-azure to version 5.14.21-150500.33.66.1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-azure package and not the kernel-azure package as distributed by SLES.
See How to fix? for SLES:15.5 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_mpls: Fix warning during failed attribute validation
The 'TCA_MPLS_LABEL' attribute is of 'NLA_U32' type, but has a validation type of 'NLA_VALIDATE_FUNCTION'. This is an invalid combination according to the comment above 'struct nla_policy':
" Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN: NLA_BINARY Validation function called for the attribute. All other Unused - but note that it's a union "
This can trigger the warning [1] in nla_get_range_unsigned() when validation of the attribute fails. Despite being of 'NLA_U32' type, the associated 'min'/'max' fields in the policy are negative as they are aliased by the 'validate' field.
Fix by changing the attribute type to 'NLA_BINARY' which is consistent with the above comment and all other users of NLA_POLICY_VALIDATE_FN(). As a result, move the length validation to the validation function.
No regressions in MPLS tests:
./tdc.py -f tc-tests/actions/mpls.json
[...]
echo $?
0
[1] WARNING: CPU: 0 PID: 17743 at lib/nlattr.c:118 nla_get_range_unsigned+0x1d8/0x1e0 lib/nlattr.c:117 Modules linked in: CPU: 0 PID: 17743 Comm: syz-executor.0 Not tainted 6.1.0-rc8 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014 RIP: 0010:nla_get_range_unsigned+0x1d8/0x1e0 lib/nlattr.c:117 [...] Call Trace: <TASK> __netlink_policy_dump_write_attr+0x23d/0x990 net/netlink/policy.c:310 netlink_policy_dump_write_attr+0x22/0x30 net/netlink/policy.c:411 netlink_ack_tlv_fill net/netlink/af_netlink.c:2454 [inline] netlink_ack+0x546/0x760 net/netlink/af_netlink.c:2506 netlink_rcv_skb+0x1b7/0x240 net/netlink/af_netlink.c:2546 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:6109 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x5e9/0x6b0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x739/0x860 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x38f/0x500 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x197/0x230 net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __x64_sys_sendmsg+0x42/0x50 net/socket.c:2572 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd
References
- https://www.suse.com/security/cve/CVE-2023-52906.html
- https://bugzilla.suse.com/1229527
- https://git.kernel.org/stable/c/2b157c3c5d6b8ddca48d53c9e662032f65af8d61
- https://git.kernel.org/stable/c/453277feb41c2235cf2c0de9209eef962c401457
- https://git.kernel.org/stable/c/8a97b544b98e44f596219ebb290fd2ba2fd5d644
- https://git.kernel.org/stable/c/9e17f99220d111ea031b44153fdfe364b0024ff2
- https://git.kernel.org/stable/c/9e2c38827cdc6fdd3bb375c8607fc04d289756f9