In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: fs, lock FTE when checking if active
The referenced commits introduced a two-step process for deleting FTEs:
- Lock the FTE, delete it from hardware, set the hardware deletion function
to NULL and unlock the FTE.
- Lock the parent flow group, delete the software copy of the FTE, and
remove it from the xarray.
However, this approach encounters a race condition if a rule with the same
match value is added simultaneously. In this scenario, fs_core may set the
hardware deletion function to NULL prematurely, causing a panic during
subsequent rule deletions.
To prevent this, ensure the active flag of the FTE is checked under a lock,
which will prevent the fs_core layer from attaching a new steering rule to
an FTE that is in the process of deletion.
[ 438.967589] MOSHE: 2496 mlx5_del_flow_rules del_hw_func
[ 438.968205] ------------[ cut here ]------------
[ 438.968654] refcount_t: decrement hit 0; leaking memory.
[ 438.969249] WARNING: CPU: 0 PID: 8957 at lib/refcount.c:31 refcount_warn_saturate+0xfb/0x110
[ 438.970054] Modules linked in: act_mirred cls_flower act_gact sch_ingress openvswitch nsh mlx5_vdpa vringh vhost_iotlb vdpa mlx5_ib mlx5_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry overlay rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm ib_uverbs ib_core zram zsmalloc fuse [last unloaded: cls_flower]
[ 438.973288] CPU: 0 UID: 0 PID: 8957 Comm: tc Not tainted 6.12.0-rc1+ #8
[ 438.973888] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 438.974874] RIP: 0010:refcount_warn_saturate+0xfb/0x110
[ 438.975363] Code: 40 66 3b 82 c6 05 16 e9 4d 01 01 e8 1f 7c a0 ff 0f 0b c3 cc cc cc cc 48 c7 c7 10 66 3b 82 c6 05 fd e8 4d 01 01 e8 05 7c a0 ff <0f> 0b c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90
[ 438.976947] RSP: 0018:ffff888124a53610 EFLAGS: 00010286
[ 438.977446] RAX: 0000000000000000 RBX: ffff888119d56de0 RCX: 0000000000000000
[ 438.978090] RDX: ffff88852c828700 RSI: ffff88852c81b3c0 RDI: ffff88852c81b3c0
[ 438.978721] RBP: ffff888120fa0e88 R08: 0000000000000000 R09: ffff888124a534b0
[ 438.979353] R10: 0000000000000001 R11: 0000000000000001 R12: ffff888119d56de0
[ 438.979979] R13: ffff888120fa0ec0 R14: ffff888120fa0ee8 R15: ffff888119d56de0
[ 438.980607] FS: 00007fe6dcc0f800(0000) GS:ffff88852c800000(0000) knlGS:0000000000000000
[ 438.983984] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 438.984544] CR2: 00000000004275e0 CR3: 0000000186982001 CR4: 0000000000372eb0
[ 438.985205] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 438.985842] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 438.986507] Call Trace:
[ 438.986799]
CVE Status: Modified
Attribute | Value |
---|---|
Attack Complexity | LOW |
Attack Vector | LOCAL |
Availability Impact | HIGH |
Base Score | 5.5 |
Base Severity | MEDIUM |
Confidentiality Impact | NONE |
Integrity Impact | NONE |
Privileges Required | LOW |
Scope | UNCHANGED |
User Interaction | NONE |
Vector String | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Exploitability Score | 1.8 |
Impact Score | 3.6 |
Source | [email protected] |
Type | Primary |