CVE-2025-21973: eth: bnxt: fix kernel panic in the bnxt_get_queue_stats{rx | tx}
In the Linux kernel, the following vulnerability has been resolved:
eth: bnxt: fix kernel panic in the bnxtgetqueuestats{rx | tx}
When qstats-get operation is executed, callbacks of netdevstatsops are called. The bnxtgetqueuestats{rx | tx} collect per-queue stats from swstats in the rings. But {rx | tx | cp}ring are allocated when the interface is up. So, these rings are not allocated when the interface is down.
The qstats-get is allowed even if the interface is down. However, the bnxtgetqueuestats{rx | tx}() accesses cpring and txring without null check. So, it needs to avoid accessing rings if the interface is down.
Reproducer: ip link set $interface down ./cli.py --spec netdev.yaml --dump qstats-get OR ip link set $interface down python ./stats.py
Splat looks like: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: errorcode(0x0000) - not-present page PGD 1680fa067 P4D 1680fa067 PUD 16be3b067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 0 UID: 0 PID: 1495 Comm: python3 Not tainted 6.14.0-rc4+ #32 5cd0f999d5a15c574ac72b3e4b907341 Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 RIP: 0010:bnxtgetqueuestatsrx+0xf/0x70 [bnxten] Code: c6 87 b5 18 00 00 02 eb a2 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 01 RSP: 0018:ffffabef43cdb7e0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffffffffc04c8710 RCX: 0000000000000000 RDX: ffffabef43cdb858 RSI: 0000000000000000 RDI: ffff8d504e850000 RBP: ffff8d506c9f9c00 R08: 0000000000000004 R09: ffff8d506bcd901c R10: 0000000000000015 R11: ffff8d506bcd9000 R12: 0000000000000000 R13: ffffabef43cdb8c0 R14: ffff8d504e850000 R15: 0000000000000000 FS: 00007f2c5462b080(0000) GS:ffff8d575f600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000167fd0000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <TASK> ? die+0x20/0x70 ? pagefaultoops+0x15a/0x460 ? schedbalancefindsrcgroup+0x58d/0xd10 ? excpagefault+0x6e/0x180 ? asmexcpagefault+0x22/0x30 ? bnxtgetqueuestatsrx+0xf/0x70 [bnxten cdd546fd48563c280cfd30e9647efa420db07bf1] netdevnlstatsbynetdev+0x2b1/0x4e0 ? xasload+0x9/0xb0 ? xasfind+0x183/0x1d0 ? xafind+0x8b/0xe0 netdevnlqstatsgetdumpit+0xbf/0x1e0 genldumpit+0x31/0x90 netlinkdump+0x1a8/0x360
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.20-1 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.20 - Upgrade
Upgrade
linux/Kernelto a version that resolves this vulnerability.Fixed in 6.13.8 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.15-1 - Compensating control
Avoid accessing cp_ring and tx_ring, including qstats-get per-queue statistics, while the network interface is down because these rings are not allocated in that state.
Event History
Frequently Asked Questions
What is the severity of CVE-2025-21973?
CVE-2025-21973 has been classified as a medium severity vulnerability.
How do I fix CVE-2025-21973?
To fix CVE-2025-21973, update the Linux kernel to version 6.14.0-rc5 or later where this vulnerability has been resolved.
What systems are affected by CVE-2025-21973?
CVE-2025-21973 affects the Linux Kernel version 6.14.0-rc4 and earlier.
What type of vulnerability is CVE-2025-21973?
CVE-2025-21973 is categorized as a kernel panic vulnerability in network statistics operations.
Can CVE-2025-21973 be exploited remotely?
CVE-2025-21973 does not indicate a remote exploitation vector, as it relates to local operations.