# CVE-2026-52961: linux: In the Linux kernel, the following vulnerability has been resolved:  ceph: fix BUG_ON in __ceph_build_xattrs_blob() d...

CVE-2026-52961 is fixed in 49 products on 1 platform, first by ALAS2023-2026-1894, released June 22, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-52961
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0015
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 22, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  ceph: fix BUG_ON in __ceph_build_xattrs_blob() due to stale blob size  The generic/642 test-case can reproduce the kernel crash:  [40243.605254] ------------[ cut here ]------------ [40243.605956] kernel BUG at fs/ceph/xattr.c:918! [40243.607142] Oops: invalid opcode: 0000 [#1] SMP PTI [40243.608067] CPU: 7 UID: 0 PID: 498762 Comm: kworker/7:1 Not tainted 7.0.0-rc7+ #3 PREEMPT(full) [40243.609700] Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [40243.611820] Workqueue: ceph-msgr ceph_con_workfn [40243.612715] RIP: 0010:__ceph_build_xattrs_blob+0x1b8/0x1e0 [40243.613731] Code: 0f 84 82 fe ff ff e9 cf 8e 56 ff 48 8d 65 e8 31 c0 5b 41 5c 41 5d 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 c3 cc cc cc cc <0f> 0b 4c 8b 62 08 41 8b 85 24 07 00 00 49 83 c4 04 41 89 44 24 fc [40243.616888] RSP: 0018:ffffcc80c4d4b688 EFLAGS: 00010287 [40243.617773] RAX: 0000000000010026 RBX: 0000000000000001 RCX: 0000000000000000 [40243.618928] RDX: ffff8a773798dee0 RSI: 0000000000000000 RDI: 0000000000000000 [40243.620158] RBP: ffffcc80c4d4b6a0 R08: 0000000000000000 R09: 0000000000000000 [40243.621573] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8a75f3b58000 [40243.622907] R13: ffff8a75f3b58000 R14: 0000000000000080 R15: 000000000000bffd [40243.624054] FS:  0000000000000000(0000) GS:ffff8a787d1b4000(0000) knlGS:0000000000000000 [40243.625331] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [40243.626269] CR2: 000072f390b623c0 CR3: 000000011c02a003 CR4: 0000000000372ef0 [40243.627408] Call Trace: [40243.627839]  <TASK> [40243.628188]  __prep_cap+0x3fd/0x4a0 [40243.628789]  ? do_raw_spin_unlock+0x4e/0xe0 [40243.629474]  ceph_check_caps+0x46a/0xc80 [40243.630094]  ? __lock_acquire+0x4a2/0x2650 [40243.630773]  ? find_held_lock+0x31/0x90 [40243.631347]  ? handle_cap_grant+0x79f/0x1060 [40243.632068]  ? lock_release+0xd9/0x300 [40243.632696]  ? __mutex_unlock_slowpath+0x3e/0x340 [40243.633429]  ? lock_release+0xd9/0x300 [40243.634052]  handle_cap_grant+0xcf6/0x1060 [40243.634745]  ceph_handle_caps+0x122b/0x2110 [40243.635415]  mds_dispatch+0x5bd/0x2160 [40243.636034]  ? ceph_con_process_message+0x65/0x190 [40243.636828]  ? lock_release+0xd9/0x300 [40243.637431]  ceph_con_process_message+0x7a/0x190 [40243.638184]  ? kfree+0x311/0x4f0 [40243.638749]  ? kfree+0x311/0x4f0 [40243.639268]  process_message+0x16/0x1a0 [40243.639915]  ? sg_free_table+0x39/0x90 [40243.640572]  ceph_con_v2_try_read+0xf58/0x2120 [40243.641255]  ? lock_acquire+0xc8/0x300 [40243.641863]  ceph_con_workfn+0x151/0x820 [40243.642493]  process_one_work+0x22f/0x630 [40243.643093]  ? process_one_work+0x254/0x630 [40243.643770]  worker_thread+0x1e2/0x400 [40243.644332]  ? __pfx_worker_thread+0x10/0x10 [40243.645020]  kthread+0x109/0x140 [40243.645560]  ? __pfx_kthread+0x10/0x10 [40243.646125]  ret_from_fork+0x3f8/0x480 [40243.646752]  ? __pfx_kthread+0x10/0x10 [40243.647316]  ? __pfx_kthread+0x10/0x10 [40243.647919]  ret_from_fork_asm+0x1a/0x30 [40243.648556]  </TASK> [40243.648902] Modules linked in: overlay hctr2 libpolyval chacha libchacha adiantum libnh libpoly1305 essiv intel_rapl_msr intel_rapl_common intel_uncore_frequency_common skx_edac_common nfit kvm_intel kvm irqbypass joydev ghash_clmulni_intel aesni_intel rapl input_leds mac_hid psmouse vga16fb serio_raw vgastate floppy i2c_piix4 pata_acpi bochs qemu_fw_cfg i2c_smbus sch_fq_codel rbd dm_crypt msr parport_pc ppdev lp parport efi_pstore [40243.654766] ---[ end trace 0000000000000000 ]---  Commit d93231a6bc8a ("ceph: prevent a client from exceeding the MDS maximum xattr size") moved the required_blob_size computation to before the __build_xattrs() call, introducing a race.  __build_xattrs() releases and reacquires i_ceph_lock during execution. In that window, handle_cap_grant() may update i_xattrs.blob with a newer MDS-provided blob and bump i_xattrs.version.  When __bui ---truncated---

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | bpftool6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | bpftool6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | bpftool6.18 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | cephfs sles 15.7 | 1.0-150700.15.7.1 | [SUSE-SU-2026:5111-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5111-1.md) | Nov 7, 2026 |
| Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-default sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.73.2.150700.17.41.4 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.73.1 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-livepatch-6.12.92-122.166 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel-livepatch-6.18.33-63.124 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel-livepatch-SLE15-SP7-RT_Update_18 sles 15.7 | 1-150700.1.5.1 | [SUSE-SU-2026:3130-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3130-1.md) | Jul 20, 2026 |
| Linux | kernel-livepatch-SLE15-SP7_Update_19 sles 15.7 | 1-150700.15.3.4 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-source sles 15.7 | 6.4.0-150700.53.73.1 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.73.1 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 |
| Linux | kernel6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-debuginfo-common-aarch64 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-debuginfo-common-x86_64 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-devel amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-headers amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-modules-extra amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-modules-extra-common amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-tools amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-tools-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-tools-devel amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.18 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-devel amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-headers amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-tools amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.94-1 | [DEBIAN-CVE-2026-52961](https://patchblox.com/security/data/fix/linux/debian-cve-2026-52961.md) | Jun 25, 2026 |
| Linux | linux Debian 14 | 7.0.10-1 | [DEBIAN-CVE-2026-52961](https://patchblox.com/security/data/fix/linux/debian-cve-2026-52961.md) | Jun 25, 2026 |
| Linux | perf6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | perf6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | perf6.18 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | python3-perf6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | python3-perf6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | python3-perf6.18 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |
| Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 |

---

Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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