In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout
There is a race condition between l2cap_chan_timeout() and l2cap_chan_del(). When we use l2cap_chan_del() to delete the channel, the chan->conn will be set to null. But the conn could be dereferenced again in the mutex_lock() of l2cap_chan_timeout(). As a result the null pointer dereference bug will happen. The KASAN report triggered by POC is shown below:
[ 472.074580] ================================================================== [ 472.075284] BUG: KASAN: null-ptr-deref in mutex_lock+0x68/0xc0 [ 472.075308] Write of size 8 at addr 0000000000000158 by task kworker/0:0/7 [ 472.075308] [ 472.075308] CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.9.0-rc5-00356-g78c0094a146b #36 [ 472.075308] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4 [ 472.075308] Workqueue: events l2cap_chan_timeout [ 472.075308] Call Trace: [ 472.075308] <TASK> [ 472.075308] dump_stack_lvl+0x137/0x1a0 [ 472.075308] print_report+0x101/0x250 [ 472.075308] ? __virt_addr_valid+0x77/0x160 [ 472.075308] ? mutex_lock+0x68/0xc0 [ 472.075308] kasan_report+0x139/0x170 [ 472.075308] ? mutex_lock+0x68/0xc0 [ 472.075308] kasan_check_range+0x2c3/0x2e0 [ 472.075308] mutex_lock+0x68/0xc0 [ 472.075308] l2cap_chan_timeout+0x181/0x300 [ 472.075308] process_one_work+0x5d2/0xe00 [ 472.075308] worker_thread+0xe1d/0x1660 [ 472.075308] ? pr_cont_work+0x5e0/0x5e0 [ 472.075308] kthread+0x2b7/0x350 [ 472.075308] ? pr_cont_work+0x5e0/0x5e0 [ 472.075308] ? kthread_blkcg+0xd0/0xd0 [ 472.075308] ret_from_fork+0x4d/0x80 [ 472.075308] ? kthread_blkcg+0xd0/0xd0 [ 472.075308] ret_from_fork_asm+0x11/0x20 [ 472.075308] </TASK> [ 472.075308] ================================================================== [ 472.094860] Disabling lock debugging due to kernel taint [ 472.096136] BUG: kernel NULL pointer dereference, address: 0000000000000158 [ 472.096136] #PF: supervisor write access in kernel mode [ 472.096136] #PF: error_code(0x0002) - not-present page [ 472.096136] PGD 0 P4D 0 [ 472.096136] Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI [ 472.096136] CPU: 0 PID: 7 Comm: kworker/0:0 Tainted: G B 6.9.0-rc5-00356-g78c0094a146b #36 [ 472.096136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4 [ 472.096136] Workqueue: events l2cap_chan_timeout [ 472.096136] RIP: 0010:mutex_lock+0x88/0xc0 [ 472.096136] Code: be 08 00 00 00 e8 f8 23 1f fd 4c 89 f7 be 08 00 00 00 e8 eb 23 1f fd 42 80 3c 23 00 74 08 48 88 [ 472.096136] RSP: 0018:ffff88800744fc78 EFLAGS: 00000246 [ 472.096136] RAX: 0000000000000000 RBX: 1ffff11000e89f8f RCX: ffffffff8457c865 [ 472.096136] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88800744fc78 [ 472.096136] RBP: 0000000000000158 R08: ffff88800744fc7f R09: 1ffff11000e89f8f [ 472.096136] R10: dffffc0000000000 R11: ffffed1000e89f90 R12: dffffc0000000000 [ 472.096136] R13: 0000000000000158 R14: ffff88800744fc78 R15: ffff888007405a00 [ 472.096136] FS: 0000000000000000(0000) GS:ffff88806d200000(0000) knlGS:0000000000000000 [ 472.096136] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 472.096136] CR2: 0000000000000158 CR3: 000000000da32000 CR4: 00000000000006f0 [ 472.096136] Call Trace: [ 472.096136] <TASK> [ 472.096136] ? __die_body+0x8d/0xe0 [ 472.096136] ? page_fault_oops+0x6b8/0x9a0 [ 472.096136] ? kernelmode_fixup_or_oops+0x20c/0x2a0 [ 472.096136] ? do_user_addr_fault+0x1027/0x1340 [ 472.096136] ? _printk+0x7a/0xa0 [ 472.096136] ? mutex_lock+0x68/0xc0 [ 472.096136] ? add_taint+0x42/0xd0 [ 472.096136] ? exc_page_fault+0x6a/0x1b0 [ 472.096136] ? asm_exc_page_fault+0x26/0x30 [ 472.096136] ? mutex_lock+0x75/0xc0 [ 472.096136] ? mutex_lock+0x88/0xc0 [ 472.096136] ? mutex_lock+0x75/0xc0 [ 472.096136] l2cap_chan_timeo ---truncated---
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade kernelUpgrade kernel-headersUpgrade kernel-rt-coreUpgrade rtlaUpgrade kernel-rt-debug-modules-extraUpgrade libperfUpgrade kernel-zfcpdumpUpgrade kernel-64k-modulesUpgrade kernel-64k-coreUpgrade kernel-zfcpdump-modules-extraUpgrade kernel-modules-coreUpgrade kernel-debug-develUpgrade kernel-debug-uki-virtUpgrade python3-perfUpgrade kernel-docUpgrade kernel-modules-extraUpgrade kernel-debugUpgrade kernel-debug-coreUpgrade kernel-cross-headersUpgrade kernel-uki-virtUpgrade kernel-zfcpdump-develUpgrade kernel-devel-matchedUpgrade kernel-64k-modules-coreUpgrade kernel-coreUpgrade kernel-64k-debug-develUpgrade kernel-rt-debug-modulesUpgrade kernel-develUpgrade kernel-debug-modules-coreUpgrade kernel-modulesUpgrade kernel-rt-debug-develUpgrade kernel-64k-debug-modules-extraUpgrade kernel-64kUpgrade kernel-64k-develUpgrade kernel-zfcpdump-coreUpgrade kernel-rt-debugUpgrade kernel-rt-debug-modules-coreUpgrade kernel-rt-modulesUpgrade kernel-abi-stablelistsUpgrade kernel-64k-devel-matchedUpgrade kernel-64k-debug-modulesUpgrade kernel-64k-debug-modules-coreUpgrade kernel-debug-devel-matchedUpgrade kernel-rt-debug-coreUpgrade kernel-tools-libsUpgrade kernel-rtUpgrade kernel-zfcpdump-modulesUpgrade kernel-uki-virt-addonsUpgrade kernel-rt-develUpgrade kernel-64k-modules-extraUpgrade kernel-64k-debug-devel-matchedUpgrade kernel-rt-modules-coreUpgrade kernel-tools-libs-develUpgrade kernel-64k-debugUpgrade kernel-rt-modules-extraUpgrade rvUpgrade kernel-64k-debug-coreUpgrade kernel-zfcpdump-modules-coreUpgrade perfUpgrade kernel-toolsUpgrade kernel-debug-modulesUpgrade bpftoolUpgrade kernel-debug-modules-extraUpgrade kernel-zfcpdump-devel-matched | Dec 4, 2024 | May 14, 2024 |
| Debian | — | Upgrade linux | Jun 4, 2024 | May 14, 2024 |
| Oracle_linux | — | Upgrade kernel | Nov 27, 2024 | May 13, 2024 |
| Redhat_linux | — | Upgrade kernelNo solution existsUpgrade kernel-rt | Sep 25, 2024 | May 14, 2024 |
| Rocky_linux | — | Upgrade perf-debuginfoUpgrade kernel-tools-libs-develUpgrade python3-perfUpgrade kernel-headersUpgrade kernel-debug-modules-extraUpgrade perfUpgrade bpftoolUpgrade kernel-debug-coreUpgrade python3-perf-debuginfoUpgrade kernel-debugUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-debug-modulesUpgrade bpftool-debuginfoUpgrade kernel-toolsUpgrade kernel-cross-headersUpgrade kernel-tools-debuginfoUpgrade kernel-modulesUpgrade kernel-debuginfoUpgrade kernel-debug-develUpgrade kernel-debug-debuginfoUpgrade kernel-tools-libsUpgrade kernel-modules-extraUpgrade kernelUpgrade kernel-develUpgrade kernel-core | Feb 5, 2026 | Dec 19, 2024 |
| Suse | — | Upgrade kernel-default-baseUpgrade dtb-socionextUpgrade kernel-devel-rtUpgrade kernel-macrosUpgrade kernel-obs-qaUpgrade kernel-64kb-extraUpgrade cluster-md-kmp-defaultUpgrade dtb-amdUpgrade kernel-defaultUpgrade dlm-kmp-azureUpgrade kernel-symsUpgrade dtb-sprdUpgrade dtb-mediatekUpgrade dlm-kmp-rtUpgrade cluster-md-kmp-64kbUpgrade dtb-nvidiaUpgrade reiserfs-kmp-defaultUpgrade kernel-64kb-develUpgrade kernel-default-extraUpgrade kselftests-kmp-rtUpgrade kernel-default-base-rebuildUpgrade reiserfs-kmp-rtUpgrade dtb-amlogicUpgrade kernel-rt_debugUpgrade dtb-apmUpgrade kernel-kvmsmallUpgrade kernel-default-manUpgrade dtb-armUpgrade kernel-docsUpgrade kernel-rt_debug-livepatch-develUpgrade kernel-rt-develUpgrade kernel-syms-rtUpgrade dtb-renesasUpgrade ocfs2-kmp-rtUpgrade kernel-azure-vdsoUpgrade kernel-debug-develUpgrade reiserfs-kmp-azureUpgrade kernel-rt_debug-vdsoUpgrade kernel-rt-livepatch-develUpgrade dtb-rockchipUpgrade kselftests-kmp-defaultUpgrade kernel-default-livepatch-develUpgrade kernel-debug-livepatch-develUpgrade dlm-kmp-defaultUpgrade kernel-kvmsmall-vdsoUpgrade kernel-rt-extraUpgrade kernel-devel-azureUpgrade kernel-rt-vdsoUpgrade kernel-azure-baseUpgrade dtb-freescaleUpgrade dtb-broadcomUpgrade cluster-md-kmp-rtUpgrade dtb-marvellUpgrade gfs2-kmp-64kbUpgrade gfs2-kmp-defaultUpgrade ocfs2-kmp-64kbUpgrade kernel-syms-azureUpgrade kernel-rt-livepatchUpgrade kernel-azure-optionalUpgrade kernel-source-rtUpgrade dtb-lgUpgrade dtb-appleUpgrade dtb-allwinnerUpgrade kernel-azure-livepatch-develUpgrade kernel-64kb-optionalUpgrade kernel-64kbUpgrade gfs2-kmp-azureUpgrade kselftests-kmp-64kbUpgrade kernel-obs-buildUpgrade kernel-debugUpgrade dtb-exynosUpgrade dtb-qcomUpgrade dlm-kmp-64kbUpgrade cluster-md-kmp-azureUpgrade kernel-rt_debug-develUpgrade kernel-kvmsmall-develUpgrade kernel-debug-vdsoUpgrade kernel-azure-develUpgrade kernel-64kb-livepatch-develUpgrade ocfs2-kmp-azureUpgrade kernel-rtUpgrade kernel-default-optionalUpgrade kernel-azureUpgrade dtb-hisiliconUpgrade kernel-kvmsmall-livepatch-develUpgrade kernel-develUpgrade gfs2-kmp-rtUpgrade ocfs2-kmp-defaultUpgrade dtb-alteraUpgrade kernel-source-azureUpgrade kernel-default-livepatchUpgrade kselftests-kmp-azureUpgrade kernel-source-vanillaUpgrade kernel-docs-htmlUpgrade kernel-zfcpdumpUpgrade kernel-default-develUpgrade kernel-sourceUpgrade dtb-xilinxUpgrade dtb-caviumUpgrade kernel-default-vdsoUpgrade reiserfs-kmp-64kbUpgrade kernel-azure-extraUpgrade dtb-amazonUpgrade kernel-rt-optional | Jun 13, 2024 | May 14, 2024 |
| Ubuntu | — | Upgrade linux-image-5.4.0-1042-iotUpgrade linux-image-azure-fde-lts-22.04Upgrade linux-image-5.15.0-118-lowlatency-64kUpgrade linux-image-gke-5.15Upgrade linux-image-snapdragon-hwe-18.04Upgrade linux-image-oem-24.04Upgrade linux-image-5.4.0-1114-raspiUpgrade linux-image-oemUpgrade linux-image-5.15.0-1064-gkeUpgrade linux-image-intel-iotgUpgrade linux-image-azure-lts-22.04Upgrade linux-image-intelUpgrade linux-image-raspi2Upgrade linux-image-6.8.0-40-generic-64kUpgrade linux-image-6.8.0-1013-awsUpgrade linux-image-gcp-lts-22.04Upgrade linux-image-oem-20.04bUpgrade linux-image-6.8.0-1010-ibmUpgrade linux-image-5.4.0-192-generic-lpaeUpgrade linux-image-azure-lts-20.04Upgrade linux-image-lowlatency-64kUpgrade linux-image-6.8.0-40-lowlatencyUpgrade linux-image-aws-lts-20.04Upgrade linux-image-oem-osp1Upgrade linux-image-5.15.0-1070-azureUpgrade linux-image-genericUpgrade linux-image-generic-64k-hwe-20.04Upgrade linux-image-5.4.0-192-lowlatencyUpgrade linux-image-gkeop-5.4Upgrade linux-image-generic-64kUpgrade linux-image-5.4.0-1090-bluefieldUpgrade linux-image-lowlatencyUpgrade linux-image-5.4.0-1135-azureUpgrade linux-image-6.8.0-40-lowlatency-64kUpgrade linux-image-ibm-lts-20.04Upgrade linux-image-5.4.0-1118-kvmUpgrade linux-image-5.15.0-1060-ibmUpgrade linux-image-azure-fdeUpgrade linux-image-6.8.0-1012-azure-fdeUpgrade linux-image-generic-lpaeUpgrade linux-image-azureUpgrade linux-image-5.15.0-1060-raspiUpgrade linux-image-nvidiaUpgrade linux-image-5.4.0-1134-gcpUpgrade linux-image-aws-lts-22.04Upgrade linux-image-ibmUpgrade linux-image-xilinx-zynqmpUpgrade linux-image-oracle-lts-20.04Upgrade linux-image-raspiUpgrade linux-image-gkeopUpgrade linux-image-oem-20.04cUpgrade linux-image-lowlatency-hwe-20.04Upgrade linux-image-6.8.0-1012-gcpUpgrade linux-image-ibm-classicUpgrade linux-image-gkeop-5.15Upgrade linux-image-5.15.0-1067-awsUpgrade linux-image-generic-hwe-18.04Upgrade linux-image-oem-20.04dUpgrade linux-image-5.15.0-1070-azure-fdeUpgrade linux-image-5.15.0-118-lowlatencyUpgrade linux-image-generic-lpae-hwe-20.04Upgrade linux-image-6.8.0-1010-oemUpgrade linux-image-6.8.0-1009-raspiUpgrade linux-image-lowlatency-hwe-18.04Upgrade linux-image-kvmUpgrade linux-image-5.15.0-1062-nvidiaUpgrade linux-image-nvidia-lowlatency-64kUpgrade linux-image-6.8.0-1012-azureUpgrade linux-image-5.15.0-118-generic-64kUpgrade linux-image-awsUpgrade linux-image-gcp-lts-20.04Upgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-azure-cvmUpgrade linux-image-nvidia-64k-6.8Upgrade linux-image-6.8.0-1011-nvidiaUpgrade linux-image-virtualUpgrade linux-image-gkeUpgrade linux-image-bluefieldUpgrade linux-image-oem-20.04Upgrade linux-image-gcpUpgrade linux-image-6.8.0-40-genericUpgrade linux-image-5.15.0-118-genericUpgrade linux-image-generic-hwe-20.04Upgrade linux-image-5.4.0-1049-xilinx-zynqmpUpgrade linux-image-5.4.0-1097-gkeopUpgrade linux-image-virtual-hwe-18.04Upgrade linux-image-oracle-lts-22.04Upgrade linux-image-5.15.0-1066-gcpUpgrade linux-image-6.8.0-1008-gkeUpgrade linux-image-5.4.0-1129-oracleUpgrade linux-image-virtual-hwe-24.04Upgrade linux-image-lowlatency-64k-hwe-20.04Upgrade linux-image-nvidia-64kUpgrade linux-image-5.15.0-1062-nvidia-lowlatencyUpgrade linux-image-5.15.0-1062-intel-iotgUpgrade linux-image-6.8.0-1011-nvidia-64kUpgrade linux-image-oracleUpgrade linux-image-6.8.0-1011-nvidia-lowlatency-64kUpgrade linux-image-5.4.0-1077-ibmUpgrade linux-image-5.4.0-1130-awsUpgrade linux-image-virtual-hwe-20.04Upgrade linux-image-nvidia-6.8Upgrade linux-image-6.8.0-1011-nvidia-lowlatencyUpgrade linux-image-5.15.0-1064-kvmUpgrade linux-image-5.15.0-1065-oracleUpgrade linux-image-nvidia-lowlatencyUpgrade linux-image-6.8.0-1010-oracleUpgrade linux-image-5.15.0-1035-xilinx-zynqmpUpgrade linux-image-6.8.0-1010-oracle-64kUpgrade linux-image-raspi-nolpaeUpgrade linux-image-oem-24.04aUpgrade linux-image-oracle-64kUpgrade linux-image-5.15.0-1050-gkeopUpgrade linux-image-5.15.0-118-generic-lpaeUpgrade linux-image-raspi-hwe-18.04Upgrade linux-image-generic-hwe-24.04Upgrade linux-image-ibm-lts-24.04Upgrade linux-image-5.4.0-192-generic | Aug 9, 2024 | May 14, 2024 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Jan 20, 2025 | May 13, 2024 |
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