In the Linux kernel, the following vulnerability has been resolved:
io_uring: check for non-NULL file pointer in io_file_can_poll()
In earlier kernels, it was possible to trigger a NULL pointer dereference off the forced async preparation path, if no file had been assigned. The trace leading to that looks as follows:
BUG: kernel NULL pointer dereference, address: 00000000000000b0 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 67 PID: 1633 Comm: buf-ring-invali Not tainted 6.8.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 2/2/2022 RIP: 0010:io_buffer_select+0xc3/0x210 Code: 00 00 48 39 d1 0f 82 ae 00 00 00 48 81 4b 48 00 00 01 00 48 89 73 70 0f b7 50 0c 66 89 53 42 85 ed 0f 85 d2 00 00 00 48 8b 13 <48> 8b 92 b0 00 00 00 48 83 7a 40 00 0f 84 21 01 00 00 4c 8b 20 5b RSP: 0018:ffffb7bec38c7d88 EFLAGS: 00010246 RAX: ffff97af2be61000 RBX: ffff97af234f1700 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffff97aecfb04820 RDI: ffff97af234f1700 RBP: 0000000000000000 R08: 0000000000200030 R09: 0000000000000020 R10: ffffb7bec38c7dc8 R11: 000000000000c000 R12: ffffb7bec38c7db8 R13: ffff97aecfb05800 R14: ffff97aecfb05800 R15: ffff97af2be5e000 FS: 00007f852f74b740(0000) GS:ffff97b1eeec0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000b0 CR3: 000000016deab005 CR4: 0000000000370ef0 Call Trace: <TASK> ? __die+0x1f/0x60 ? page_fault_oops+0x14d/0x420 ? do_user_addr_fault+0x61/0x6a0 ? exc_page_fault+0x6c/0x150 ? asm_exc_page_fault+0x22/0x30 ? io_buffer_select+0xc3/0x210 __io_import_iovec+0xb5/0x120 io_readv_prep_async+0x36/0x70 io_queue_sqe_fallback+0x20/0x260 io_submit_sqes+0x314/0x630 __do_sys_io_uring_enter+0x339/0xbc0 ? __do_sys_io_uring_register+0x11b/0xc50 ? vm_mmap_pgoff+0xce/0x160 do_syscall_64+0x5f/0x180 entry_SYSCALL_64_after_hwframe+0x46/0x4e RIP: 0033:0x55e0a110a67e Code: ba cc 00 00 00 45 31 c0 44 0f b6 92 d0 00 00 00 31 d2 41 b9 08 00 00 00 41 83 e2 01 41 c1 e2 04 41 09 c2 b8 aa 01 00 00 0f 05 <c3> 90 89 30 eb a9 0f 1f 40 00 48 8b 42 20 8b 00 a8 06 75 af 85 f6
because the request is marked forced ASYNC and has a bad file fd, and hence takes the forced async prep path.
Current kernels with the request async prep cleaned up can no longer hit this issue, but for ease of backporting, let's add this safety check in here too as it really doesn't hurt. For both cases, this will inevitably end with a CQE posted with -EBADF.
CVSS Details
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade kernel-develUpgrade perf-debuginfoUpgrade perfUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-headersUpgrade kernel-modules-extra-commonUpgrade kernel-tools-develUpgrade python3-perfUpgrade kernel-toolsUpgrade kernel-livepatch-6.1.96-102.177Upgrade python3-perf-debuginfoUpgrade kernel-libbpf-staticUpgrade kernel-libbpfUpgrade kernel-modules-extraUpgrade kernel-tools-debuginfoUpgrade kernel-debuginfoUpgrade kernel-debuginfo-common-x86_64Upgrade bpftoolUpgrade bpftool-debuginfoUpgrade kernel-libbpf-develUpgrade kernel | Jun 11, 2025 | Jun 25, 2024 |
| Debian | — | Upgrade linuxUpgrade linux-6.1 | Jul 18, 2024 | Jun 25, 2024 |
| Suse | — | Upgrade dtb-amdUpgrade kernel-debug-develUpgrade kernel-64kb-develUpgrade dtb-socionextUpgrade kernel-64kb-extraUpgrade kernel-default-optionalUpgrade reiserfs-kmp-defaultUpgrade kernel-debugUpgrade kernel-rt_debug-livepatch-develUpgrade kernel-azure-extraUpgrade ocfs2-kmp-azureUpgrade dtb-marvellUpgrade dtb-appleUpgrade dtb-caviumUpgrade cluster-md-kmp-64kbUpgrade kernel-docsUpgrade kernel-default-develUpgrade kernel-defaultUpgrade dtb-mediatekUpgrade kernel-rt_debugUpgrade kernel-symsUpgrade kernel-64kbUpgrade dtb-sprdUpgrade kernel-rt-livepatchUpgrade gfs2-kmp-defaultUpgrade kernel-kvmsmall-livepatch-develUpgrade kernel-develUpgrade kernel-azure-optionalUpgrade kernel-default-livepatchUpgrade dtb-amazonUpgrade dtb-armUpgrade kernel-devel-rtUpgrade dlm-kmp-rtUpgrade kernel-64kb-livepatch-develUpgrade dtb-renesasUpgrade kernel-default-baseUpgrade kernel-default-livepatch-develUpgrade kernel-rt-develUpgrade dtb-allwinnerUpgrade dtb-freescaleUpgrade dtb-xilinxUpgrade cluster-md-kmp-rtUpgrade kernel-64kb-optionalUpgrade gfs2-kmp-azureUpgrade dtb-alteraUpgrade kselftests-kmp-rtUpgrade gfs2-kmp-64kbUpgrade reiserfs-kmp-rtUpgrade ocfs2-kmp-defaultUpgrade dtb-hisiliconUpgrade dlm-kmp-defaultUpgrade dlm-kmp-64kbUpgrade kselftests-kmp-azureUpgrade dtb-qcomUpgrade kernel-debug-livepatch-develUpgrade kernel-azure-vdsoUpgrade kernel-azure-develUpgrade dlm-kmp-azureUpgrade kernel-debug-vdsoUpgrade gfs2-kmp-rtUpgrade dtb-lgUpgrade dtb-amlogicUpgrade reiserfs-kmp-64kbUpgrade kernel-source-azureUpgrade kernel-zfcpdumpUpgrade kernel-azureUpgrade dtb-apmUpgrade kernel-obs-qaUpgrade kernel-rt_debug-develUpgrade kernel-syms-rtUpgrade kernel-obs-buildUpgrade dtb-rockchipUpgrade dtb-broadcomUpgrade kernel-rt_debug-vdsoUpgrade kselftests-kmp-64kbUpgrade kernel-syms-azureUpgrade cluster-md-kmp-defaultUpgrade kernel-docs-htmlUpgrade kernel-macrosUpgrade kernel-kvmsmallUpgrade dtb-exynosUpgrade kernel-sourceUpgrade kernel-rtUpgrade kernel-rt-vdsoUpgrade kernel-default-vdsoUpgrade dtb-nvidiaUpgrade cluster-md-kmp-azureUpgrade ocfs2-kmp-rtUpgrade kernel-default-extraUpgrade kernel-azure-livepatch-develUpgrade reiserfs-kmp-azureUpgrade kselftests-kmp-defaultUpgrade kernel-default-base-rebuildUpgrade kernel-source-rtUpgrade ocfs2-kmp-64kbUpgrade kernel-source-vanillaUpgrade kernel-rt-extraUpgrade kernel-devel-azureUpgrade kernel-rt-optionalUpgrade kernel-rt-livepatch-develUpgrade kernel-kvmsmall-vdsoUpgrade kernel-kvmsmall-devel | Jul 23, 2024 | Jun 25, 2024 |
| Ubuntu | — | Upgrade linux-image-azure-fdeUpgrade linux-image-ibm-lts-24.04Upgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-oracleUpgrade linux-image-kvmUpgrade linux-image-ibm-classicUpgrade linux-image-nvidia-64k-6.8Upgrade linux-image-raspiUpgrade linux-image-6.8.0-1014-azureUpgrade linux-image-oem-22.04bUpgrade linux-image-6.8.0-1010-gkeUpgrade linux-image-nvidia-lowlatency-64kUpgrade linux-image-awsUpgrade linux-image-gcpUpgrade linux-image-ibmUpgrade linux-image-nvidia-64kUpgrade linux-image-generic-hwe-24.04Upgrade linux-image-6.8.0-44-generic-64kUpgrade linux-image-oracle-64kUpgrade linux-image-6.8.0-1014-azure-fdeUpgrade linux-image-6.8.0-45-genericUpgrade linux-image-generic-hwe-22.04Upgrade linux-image-nvidia-lowlatencyUpgrade linux-image-6.8.0-1013-nvidia-64kUpgrade linux-image-generic-64k-hwe-22.04Upgrade linux-image-virtual-hwe-22.04Upgrade linux-image-genericUpgrade linux-image-generic-lpaeUpgrade linux-image-virtual-hwe-24.04Upgrade linux-image-6.8.0-1011-raspiUpgrade linux-image-6.8.0-45-generic-64kUpgrade linux-image-nvidia-6.8Upgrade linux-image-azureUpgrade linux-image-6.8.0-1012-ibmUpgrade linux-image-6.8.0-1014-gcpUpgrade linux-image-6.8.0-1012-oemUpgrade linux-image-6.8.0-1015-awsUpgrade linux-image-oem-22.04cUpgrade linux-image-6.8.0-1012-oracleUpgrade linux-image-lowlatencyUpgrade linux-image-generic-64kUpgrade linux-image-virtualUpgrade linux-image-oem-22.04aUpgrade linux-image-lowlatency-hwe-22.04Upgrade linux-image-oem-22.04dUpgrade linux-image-6.8.0-44-genericUpgrade linux-image-lowlatency-64k-hwe-22.04Upgrade linux-image-oem-22.04Upgrade linux-image-6.8.0-1013-nvidia-lowlatencyUpgrade linux-image-6.8.0-44-lowlatencyUpgrade linux-image-nvidiaUpgrade linux-image-6.8.0-44-lowlatency-64kUpgrade linux-image-6.8.0-1013-nvidiaUpgrade linux-image-6.8.0-1013-nvidia-lowlatency-64kUpgrade linux-image-6.8.0-1012-oracle-64kUpgrade linux-image-gkeUpgrade linux-image-lowlatency-64k | Sep 12, 2024 | Jun 25, 2024 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Oct 14, 2025 | Jun 25, 2024 |
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