medium CVSS 5.5 EPSS <0.1%

CVE-2023-52782·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Track xmit submission to PTP WQ after populating metadata map Ensure the skb is available in metadata mapping to skbs before tracking the metadata index for detecting undelivered CQEs. If the metadata index is put in the tracking list before putting the skb in the map, the metadata index might be used for detecting undelivered CQEs before the relevant skb is available in the map, which can lead to a null-ptr-deref. Log: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 0 PID: 1243 Comm: kworker/0:2 Not tainted 6.6.0-rc4+ #108 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: events mlx5e_rx_dim_work [mlx5_core] RIP: 0010:mlx5e_ptp_napi_poll+0x9a4/0x2290 [mlx5_core] Code: 8c 24 38 cc ff ff 4c 8d 3c c1 4c 89 f9 48 c1 e9 03 42 80 3c 31 00 0f 85 97 0f 00 00 4d 8b 3f 49 8d 7f 28 48 89 f9 48 c1 e9 03 <42> 80 3c 31 00 0f 85 8b 0f 00 00 49 8b 47 28 48 85 c0 0f 84 05 07 RSP: 0018:ffff8884d3c09c88 EFLAGS: 00010206 RAX: 0000000000000069 RBX: ffff8881160349d8 RCX: 0000000000000005 RDX: ffffed10218f48cf RSI: 0000000000000004 RDI: 0000000000000028 RBP: ffff888122707700 R08: 0000000000000001 R09: ffffed109a781383 R10: 0000000000000003 R11: 0000000000000003 R12: ffff88810c7a7a40 R13: ffff888122707700 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8884d3c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4f878dd6e0 CR3: 000000014d108002 CR4: 0000000000370eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> ? die_addr+0x3c/0xa0 ? exc_general_protection+0x144/0x210 ? asm_exc_general_protection+0x22/0x30 ? mlx5e_ptp_napi_poll+0x9a4/0x2290 [mlx5_core] ? mlx5e_ptp_napi_poll+0x8f6/0x2290 [mlx5_core] __napi_poll.constprop.0+0xa4/0x580 net_rx_action+0x460/0xb80 ? _raw_spin_unlock_irqrestore+0x32/0x60 ? __napi_poll.constprop.0+0x580/0x580 ? tasklet_action_common.isra.0+0x2ef/0x760 __do_softirq+0x26c/0x827 irq_exit_rcu+0xc2/0x100 common_interrupt+0x7f/0xa0 </IRQ> <TASK> asm_common_interrupt+0x22/0x40 RIP: 0010:__kmem_cache_alloc_node+0xb/0x330 Code: 41 5d 41 5e 41 5f c3 8b 44 24 14 8b 4c 24 10 09 c8 eb d5 e8 b7 43 ca 01 0f 1f 80 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 57 <41> 56 41 89 d6 41 55 41 89 f5 41 54 49 89 fc 53 48 83 e4 f0 48 83 RSP: 0018:ffff88812c4079c0 EFLAGS: 00000246 RAX: 1ffffffff083c7fe RBX: ffff888100042dc0 RCX: 0000000000000218 RDX: 00000000ffffffff RSI: 0000000000000dc0 RDI: ffff888100042dc0 RBP: ffff88812c4079c8 R08: ffffffffa0289f96 R09: ffffed1025880ea9 R10: ffff888138839f80 R11: 0000000000000002 R12: 0000000000000dc0 R13: 0000000000000100 R14: 000000000000008c R15: ffff8881271fc450 ? cmd_exec+0x796/0x2200 [mlx5_core] kmalloc_trace+0x26/0xc0 cmd_exec+0x796/0x2200 [mlx5_core] mlx5_cmd_do+0x22/0xc0 [mlx5_core] mlx5_cmd_exec+0x17/0x30 [mlx5_core] mlx5_core_modify_cq_moderation+0x139/0x1b0 [mlx5_core] ? mlx5_add_cq_to_tasklet+0x280/0x280 [mlx5_core] ? lockdep_set_lock_cmp_fn+0x190/0x190 ? process_one_work+0x659/0x1220 mlx5e_rx_dim_work+0x9d/0x100 [mlx5_core] process_one_work+0x730/0x1220 ? lockdep_hardirqs_on_prepare+0x400/0x400 ? max_active_store+0xf0/0xf0 ? assign_work+0x168/0x240 worker_thread+0x70f/0x12d0 ? __kthread_parkme+0xd1/0x1d0 ? process_one_work+0x1220/0x1220 kthread+0x2d9/0x3b0 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x2d/0x70 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork_as ---truncated---

Severity
medium
Software
Kernel
Fixed in
6.6.3
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 26% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Affected versions

From: 6.6

Until: 6.6.3

Fixed in: 6.6.3

How to fix this CVE

Update the Linux kernel to version 6.6.3 or later to resolve a critical race condition in the mlx5e PTP driver that can cause null pointer dereferences. Systems running kernel versions 6.6.0 through 6.6.2 should prioritize this update, particularly if they utilize Mellanox ConnectX network adapters with PTP functionality enabled.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check the installed kernel version with `uname -r` and compare against 6.6.0-6.6.2 (vulnerable range)
  2. Step 2: Verify if mlx5 driver is loaded with `lsmod | grep mlx5` to determine if Mellanox hardware is present
  3. Step 3: Search kernel logs for 'general protection fault' or 'mlx5e_ptp_napi_poll' errors with `sudo dmesg | grep -i 'general protection\|mlx5e_ptp'`
  4. Step 4: After patching, run `uname -r` again and confirm the kernel version is 6.6.3 or higher

FAQ

What is CVE-2023-52782?

This vulnerability is a race condition in the Linux kernel's mlx5e Mellanox driver where packet metadata tracking in the PTP (Precision Time Protocol) work queue can be recorded before the associated socket buffer is available in memory, causing null pointer dereferences during network packet processing.

Is CVE-2023-52782 being actively exploited?

No, CVE-2023-52782 is not listed in the CISA Known Exploited Vulnerabilities catalog and has no known public exploits. It is a kernel stability issue rather than a remote code execution vulnerability.

What versions of Kernel are affected by CVE-2023-52782?

Linux kernel versions 6.6.0 through 6.6.2 are vulnerable. The issue was fixed in version 6.6.3 and later.

How do I check if my server is vulnerable to CVE-2023-52782?

Run `uname -r` to check your kernel version. If it returns 6.6.0, 6.6.1, or 6.6.2 and you have Mellanox hardware, execute `lsmod | grep mlx5` to confirm exposure.

Does Defensia detect CVE-2023-52782?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2023-52782 will appear in your dashboard with remediation steps.

Related Kernel CVEs

CVE-2026-63795CVSS 10In the Linux kernel, the following vulnerability has been resolved: 9p: avoid putting oldfid in p9_client_walk() error path When p9_client_walk() is called with clone set to false, fid aliases oldfid. If the walk subsequently fails after the request has been sent, the error path jumps to clunk_fid, which currently calls p9_fid_put(fid) unconditionally. This drops a reference to oldfid even though ownership of oldfid remains with the caller. If this is the last reference, oldfid can be clunked and destroyed while the caller still expects it to be valid. A later use or put of oldfid can then trigger a use-after-free or refcount underflow. Fix this by only putting fid in the clunk_fid error path when it does not alias oldfid, matching the existing guard in the error path below. This can be triggered when a multi-component walk is split into multiple p9_client_walk() calls and a later non-cloning walk fails. A reproducer and refcount warning logs are available on request.
CVE-2026-46325CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE The current implementation incorrectly handles memory regions (MRs) with page sizes different from the system PAGE_SIZE. The core issue is that rxe_set_page() is called with mr->page_size step increments, but the page_list stores individual struct page pointers, each representing PAGE_SIZE of memory. ib_sg_to_page() has ensured that when i>=1 either a) SG[i-1].dma_end and SG[i].dma_addr are contiguous or b) SG[i-1].dma_end and SG[i].dma_addr are mr->page_size aligned. This leads to incorrect iova-to-va conversion in scenarios: 1) page_size < PAGE_SIZE (e.g., MR: 4K, system: 64K): ibmr->iova = 0x181800 sg[0]: dma_addr=0x181800, len=0x800 sg[1]: dma_addr=0x173000, len=0x1000 Access iova = 0x181800 + 0x810 = 0x182010 Expected VA: 0x173010 (second SG, offset 0x10) Before fix: - index = (0x182010 >> 12) - (0x181800 >> 12) = 1 - page_offset = 0x182010 & 0xFFF = 0x10 - xarray[1] stores system page base 0x170000 - Resulting VA: 0x170000 + 0x10 = 0x170010 (wrong) 2) page_size > PAGE_SIZE (e.g., MR: 64K, system: 4K): ibmr->iova = 0x18f800 sg[0]: dma_addr=0x18f800, len=0x800 sg[1]: dma_addr=0x170000, len=0x1000 Access iova = 0x18f800 + 0x810 = 0x190010 Expected VA: 0x170010 (second SG, offset 0x10) Before fix: - index = (0x190010 >> 16) - (0x18f800 >> 16) = 1 - page_offset = 0x190010 & 0xFFFF = 0x10 - xarray[1] stores system page for dma_addr 0x170000 - Resulting VA: system page of 0x170000 + 0x10 = 0x170010 (wrong) Yi Zhang reported a kernel panic[1] years ago related to this defect. Solution: 1. Replace xarray with pre-allocated rxe_mr_page array for sequential indexing (all MR page indices are contiguous) 2. Each rxe_mr_page stores both struct page* and offset within the system page 3. Handle MR page_size != PAGE_SIZE relationships: - page_size > PAGE_SIZE: Split MR pages into multiple system pages - page_size <= PAGE_SIZE: Store offset within system page 4. Add boundary checks and compatibility validation This ensures correct iova-to-va conversion regardless of MR page size and system PAGE_SIZE relationship, while improving performance through array-based sequential access. Tests on 4K and 64K PAGE_SIZE hosts: - rdma-core/pytests $ ./build/bin/run_tests.py --dev eth0_rxe - blktest: $ TIMEOUT=30 QUICK_RUN=1 USE_RXE=1 NVMET_TRTYPES=rdma ./check nvme srp rnbd [1] https://lore.kernel.org/all/CAHj4cs9XRqE25jyVw9rj9YugffLn5+f=1znaBEnu1usLOciD+g@mail.gmail.com/T/
CVE-2026-52914CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: batman-adv: fix fragment reassembly length accounting batman-adv keeps a running payload length for queued fragments and uses it to validate a fragment chain before reassembly. That accounting currently allows the accumulated fragment length to be truncated during updates. As a result, malformed fragment chains can bypass the intended validation and drive reassembly with inconsistent length state, leading to a local denial of service. Fix the accounting by storing the accumulated length in a length-typed field and rejecting update overflows before the existing validation logic runs. The fix was verified against the original reproducer and against valid fragment reassembly paths.
CVE-2026-53151CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix the ACK parser to extract the SACK table for parsing Fix modification of the received skbuff in rxrpc_input_soft_acks() and a potential incorrect access of the buffer in a fragmented UDP packet (the packet would probably have to be deliberately pre-generated as fragmented) when AF_RXRPC tries to extract the contents of the SACK table by copying out the contents of the SACK table into a buffer before attempting to parse AF_RXRPC assumes that it can just call skb_condense() and then validly access the SACK table from skb->data and that it will be a flat buffer - but skb_condense() can silently fail to do anything under some circumstances. Note that whilst rxrpc_input_soft_acks() should be able to parse extended ACKs, the rest of AF_RXRPC doesn't currently support that. Further, there's then no need to call skb_condense() in rxrpc_input_ack(), so don't.
CVE-2026-63800CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: pNFS: Fix use-after-free in pnfs_update_layout() When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(), the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds, pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(), which still references 'lo'. This results in a use-after-free when the tracepoint accesses lo's fields. Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo).

References

Track CVEs across your fleet automatically

Defensia scans your Linux servers and tells you exactly which ones are running vulnerable versions — including CVE-2023-52782. Free for 1 server.

Get started free