Filtered by vendor Linux
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13271 CVE
| CVE | Vendors | Products | Updated | CVSS v2 | CVSS v3 |
|---|---|---|---|---|---|
| CVE-2024-41761 | 2 Ibm, Linux | 3 Db2, Linux On Ibm Z, Linux Kernel | 2025-01-31 | N/A | 5.3 MEDIUM |
| IBM Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) 10.5, 11.1, and 11.5 is vulnerable to a denial of service as the server may crash under certain conditions with a specially crafted query. | |||||
| CVE-2024-38574 | 1 Linux | 1 Linux Kernel | 2025-01-31 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: libbpf: Prevent null-pointer dereference when prog to load has no BTF In bpf_objec_load_prog(), there's no guarantee that obj->btf is non-NULL when passing it to btf__fd(), and this function does not perform any check before dereferencing its argument (as bpf_object__btf_fd() used to do). As a consequence, we get segmentation fault errors in bpftool (for example) when trying to load programs that come without BTF information. v2: Keep btf__fd() in the fix instead of reverting to bpf_object__btf_fd(). | |||||
| CVE-2021-47435 | 1 Linux | 1 Linux Kernel | 2025-01-31 | N/A | 4.7 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: dm: fix mempool NULL pointer race when completing IO dm_io_dec_pending() calls end_io_acct() first and will then dec md in-flight pending count. But if a task is swapping DM table at same time this can result in a crash due to mempool->elements being NULL: task1 task2 do_resume ->do_suspend ->dm_wait_for_completion bio_endio ->clone_endio ->dm_io_dec_pending ->end_io_acct ->wakeup task1 ->dm_swap_table ->__bind ->__bind_mempools ->bioset_exit ->mempool_exit ->free_io [ 67.330330] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 ...... [ 67.330494] pstate: 80400085 (Nzcv daIf +PAN -UAO) [ 67.330510] pc : mempool_free+0x70/0xa0 [ 67.330515] lr : mempool_free+0x4c/0xa0 [ 67.330520] sp : ffffff8008013b20 [ 67.330524] x29: ffffff8008013b20 x28: 0000000000000004 [ 67.330530] x27: ffffffa8c2ff40a0 x26: 00000000ffff1cc8 [ 67.330535] x25: 0000000000000000 x24: ffffffdada34c800 [ 67.330541] x23: 0000000000000000 x22: ffffffdada34c800 [ 67.330547] x21: 00000000ffff1cc8 x20: ffffffd9a1304d80 [ 67.330552] x19: ffffffdada34c970 x18: 000000b312625d9c [ 67.330558] x17: 00000000002dcfbf x16: 00000000000006dd [ 67.330563] x15: 000000000093b41e x14: 0000000000000010 [ 67.330569] x13: 0000000000007f7a x12: 0000000034155555 [ 67.330574] x11: 0000000000000001 x10: 0000000000000001 [ 67.330579] x9 : 0000000000000000 x8 : 0000000000000000 [ 67.330585] x7 : 0000000000000000 x6 : ffffff80148b5c1a [ 67.330590] x5 : ffffff8008013ae0 x4 : 0000000000000001 [ 67.330596] x3 : ffffff80080139c8 x2 : ffffff801083bab8 [ 67.330601] x1 : 0000000000000000 x0 : ffffffdada34c970 [ 67.330609] Call trace: [ 67.330616] mempool_free+0x70/0xa0 [ 67.330627] bio_put+0xf8/0x110 [ 67.330638] dec_pending+0x13c/0x230 [ 67.330644] clone_endio+0x90/0x180 [ 67.330649] bio_endio+0x198/0x1b8 [ 67.330655] dec_pending+0x190/0x230 [ 67.330660] clone_endio+0x90/0x180 [ 67.330665] bio_endio+0x198/0x1b8 [ 67.330673] blk_update_request+0x214/0x428 [ 67.330683] scsi_end_request+0x2c/0x300 [ 67.330688] scsi_io_completion+0xa0/0x710 [ 67.330695] scsi_finish_command+0xd8/0x110 [ 67.330700] scsi_softirq_done+0x114/0x148 [ 67.330708] blk_done_softirq+0x74/0xd0 [ 67.330716] __do_softirq+0x18c/0x374 [ 67.330724] irq_exit+0xb4/0xb8 [ 67.330732] __handle_domain_irq+0x84/0xc0 [ 67.330737] gic_handle_irq+0x148/0x1b0 [ 67.330744] el1_irq+0xe8/0x190 [ 67.330753] lpm_cpuidle_enter+0x4f8/0x538 [ 67.330759] cpuidle_enter_state+0x1fc/0x398 [ 67.330764] cpuidle_enter+0x18/0x20 [ 67.330772] do_idle+0x1b4/0x290 [ 67.330778] cpu_startup_entry+0x20/0x28 [ 67.330786] secondary_start_kernel+0x160/0x170 Fix this by: 1) Establishing pointers to 'struct dm_io' members in dm_io_dec_pending() so that they may be passed into end_io_acct() _after_ free_io() is called. 2) Moving end_io_acct() after free_io(). | |||||
| CVE-2023-52788 | 1 Linux | 1 Linux Kernel | 2025-01-31 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: i915/perf: Fix NULL deref bugs with drm_dbg() calls When i915 perf interface is not available dereferencing it will lead to NULL dereferences. As returning -ENOTSUPP is pretty clear return when perf interface is not available. [tursulin: added stable tag] (cherry picked from commit 36f27350ff745bd228ab04d7845dfbffc177a889) | |||||
| CVE-2024-27254 | 5 Hp, Ibm, Linux and 2 more | 7 Hp-ux, Aix, Db2 and 4 more | 2025-01-31 | N/A | 5.3 MEDIUM |
| IBM Db2 for Linux, UNIX and Windows (includes DB2 Connect Server) 10.5, 11.1, and 11.5 federated server is vulnerable to denial of service with a specially crafted query under certain conditions. IBM X-Force ID: 283813. | |||||
| CVE-2024-35946 | 1 Linux | 1 Linux Kernel | 2025-01-31 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: wifi: rtw89: fix null pointer access when abort scan During cancel scan we might use vif that weren't scanning. Fix this by using the actual scanning vif. | |||||
| CVE-2024-35945 | 1 Linux | 1 Linux Kernel | 2025-01-31 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: net: phy: phy_device: Prevent nullptr exceptions on ISR If phydev->irq is set unconditionally, check for valid interrupt handler or fall back to polling mode to prevent nullptr exceptions in interrupt service routine. | |||||
| CVE-2024-25698 | 3 Esri, Linux, Microsoft | 3 Portal For Arcgis, Linux Kernel, Windows | 2025-01-30 | N/A | 6.1 MEDIUM |
| There is a reflected cross site scripting vulnerability in the home application in Esri Portal for ArcGIS 11.1 and below on Windows and Linux that allows a remote, unauthenticated attacker to create a crafted link which when clicked could potentially execute arbitrary JavaScript code in the victim’s browser. | |||||
| CVE-2024-26893 | 1 Linux | 1 Linux Kernel | 2025-01-27 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: firmware: arm_scmi: Fix double free in SMC transport cleanup path When the generic SCMI code tears down a channel, it calls the chan_free callback function, defined by each transport. Since multiple protocols might share the same transport_info member, chan_free() might want to clean up the same member multiple times within the given SCMI transport implementation. In this case, it is SMC transport. This will lead to a NULL pointer dereference at the second time: | scmi_protocol scmi_dev.1: Enabled polling mode TX channel - prot_id:16 | arm-scmi firmware:scmi: SCMI Notifications - Core Enabled. | arm-scmi firmware:scmi: unable to communicate with SCMI | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 | Mem abort info: | ESR = 0x0000000096000004 | EC = 0x25: DABT (current EL), IL = 32 bits | SET = 0, FnV = 0 | EA = 0, S1PTW = 0 | FSC = 0x04: level 0 translation fault | Data abort info: | ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 | CM = 0, WnR = 0, TnD = 0, TagAccess = 0 | GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 | user pgtable: 4k pages, 48-bit VAs, pgdp=0000000881ef8000 | [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 | Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP | Modules linked in: | CPU: 4 PID: 1 Comm: swapper/0 Not tainted 6.7.0-rc2-00124-g455ef3d016c9-dirty #793 | Hardware name: FVP Base RevC (DT) | pstate: 61400009 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) | pc : smc_chan_free+0x3c/0x6c | lr : smc_chan_free+0x3c/0x6c | Call trace: | smc_chan_free+0x3c/0x6c | idr_for_each+0x68/0xf8 | scmi_cleanup_channels.isra.0+0x2c/0x58 | scmi_probe+0x434/0x734 | platform_probe+0x68/0xd8 | really_probe+0x110/0x27c | __driver_probe_device+0x78/0x12c | driver_probe_device+0x3c/0x118 | __driver_attach+0x74/0x128 | bus_for_each_dev+0x78/0xe0 | driver_attach+0x24/0x30 | bus_add_driver+0xe4/0x1e8 | driver_register+0x60/0x128 | __platform_driver_register+0x28/0x34 | scmi_driver_init+0x84/0xc0 | do_one_initcall+0x78/0x33c | kernel_init_freeable+0x2b8/0x51c | kernel_init+0x24/0x130 | ret_from_fork+0x10/0x20 | Code: f0004701 910a0021 aa1403e5 97b91c70 (b9400280) | ---[ end trace 0000000000000000 ]--- Simply check for the struct pointer being NULL before trying to access its members, to avoid this situation. This was found when a transport doesn't really work (for instance no SMC service), the probe routines then tries to clean up, and triggers a crash. | |||||
| CVE-2024-26879 | 1 Linux | 1 Linux Kernel | 2025-01-27 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: clk: meson: Add missing clocks to axg_clk_regmaps Some clocks were missing from axg_clk_regmaps, which caused kernel panic during cat /sys/kernel/debug/clk/clk_summary [ 57.349402] Unable to handle kernel NULL pointer dereference at virtual address 00000000000001fc ... [ 57.430002] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 57.436900] pc : regmap_read+0x1c/0x88 [ 57.440608] lr : clk_regmap_gate_is_enabled+0x3c/0xb0 [ 57.445611] sp : ffff800082f1b690 [ 57.448888] x29: ffff800082f1b690 x28: 0000000000000000 x27: ffff800080eb9a70 [ 57.455961] x26: 0000000000000007 x25: 0000000000000016 x24: 0000000000000000 [ 57.463033] x23: ffff800080e8b488 x22: 0000000000000015 x21: ffff00000e7e7000 [ 57.470106] x20: ffff00000400ec00 x19: 0000000000000000 x18: ffffffffffffffff [ 57.477178] x17: 0000000000000000 x16: 0000000000000000 x15: ffff0000042a3000 [ 57.484251] x14: 0000000000000000 x13: ffff0000042a2fec x12: 0000000005f5e100 [ 57.491323] x11: abcc77118461cefd x10: 0000000000000020 x9 : ffff8000805e4b24 [ 57.498396] x8 : ffff0000028063c0 x7 : ffff800082f1b710 x6 : ffff800082f1b710 [ 57.505468] x5 : 00000000ffffffd0 x4 : ffff800082f1b6e0 x3 : 0000000000001000 [ 57.512541] x2 : ffff800082f1b6e4 x1 : 000000000000012c x0 : 0000000000000000 [ 57.519615] Call trace: [ 57.522030] regmap_read+0x1c/0x88 [ 57.525393] clk_regmap_gate_is_enabled+0x3c/0xb0 [ 57.530050] clk_core_is_enabled+0x44/0x120 [ 57.534190] clk_summary_show_subtree+0x154/0x2f0 [ 57.538847] clk_summary_show_subtree+0x220/0x2f0 [ 57.543505] clk_summary_show_subtree+0x220/0x2f0 [ 57.548162] clk_summary_show_subtree+0x220/0x2f0 [ 57.552820] clk_summary_show_subtree+0x220/0x2f0 [ 57.557477] clk_summary_show_subtree+0x220/0x2f0 [ 57.562135] clk_summary_show_subtree+0x220/0x2f0 [ 57.566792] clk_summary_show_subtree+0x220/0x2f0 [ 57.571450] clk_summary_show+0x84/0xb8 [ 57.575245] seq_read_iter+0x1bc/0x4b8 [ 57.578954] seq_read+0x8c/0xd0 [ 57.582059] full_proxy_read+0x68/0xc8 [ 57.585767] vfs_read+0xb0/0x268 [ 57.588959] ksys_read+0x70/0x108 [ 57.592236] __arm64_sys_read+0x24/0x38 [ 57.596031] invoke_syscall+0x50/0x128 [ 57.599740] el0_svc_common.constprop.0+0x48/0xf8 [ 57.604397] do_el0_svc+0x28/0x40 [ 57.607675] el0_svc+0x34/0xb8 [ 57.610694] el0t_64_sync_handler+0x13c/0x158 [ 57.615006] el0t_64_sync+0x190/0x198 [ 57.618635] Code: a9bd7bfd 910003fd a90153f3 aa0003f3 (b941fc00) [ 57.624668] ---[ end trace 0000000000000000 ]--- [jbrunet: add missing Fixes tag] | |||||
| CVE-2023-52646 | 1 Linux | 1 Linux Kernel | 2025-01-27 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: aio: fix mremap after fork null-deref Commit e4a0d3e720e7 ("aio: Make it possible to remap aio ring") introduced a null-deref if mremap is called on an old aio mapping after fork as mm->ioctx_table will be set to NULL. [jmoyer@redhat.com: fix 80 column issue] | |||||
| CVE-2024-26866 | 1 Linux | 1 Linux Kernel | 2025-01-27 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: spi: lpspi: Avoid potential use-after-free in probe() fsl_lpspi_probe() is allocating/disposing memory manually with spi_alloc_host()/spi_alloc_target(), but uses devm_spi_register_controller(). In case of error after the latter call the memory will be explicitly freed in the probe function by spi_controller_put() call, but used afterwards by "devm" management outside probe() (spi_unregister_controller() <- devm_spi_unregister() below). Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070 ... Call trace: kernfs_find_ns kernfs_find_and_get_ns sysfs_remove_group sysfs_remove_groups device_remove_attrs device_del spi_unregister_controller devm_spi_unregister release_nodes devres_release_all really_probe driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork | |||||
| CVE-2024-26863 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-01-27 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: hsr: Fix uninit-value access in hsr_get_node() KMSAN reported the following uninit-value access issue [1]: ===================================================== BUG: KMSAN: uninit-value in hsr_get_node+0xa2e/0xa40 net/hsr/hsr_framereg.c:246 hsr_get_node+0xa2e/0xa40 net/hsr/hsr_framereg.c:246 fill_frame_info net/hsr/hsr_forward.c:577 [inline] hsr_forward_skb+0xe12/0x30e0 net/hsr/hsr_forward.c:615 hsr_dev_xmit+0x1a1/0x270 net/hsr/hsr_device.c:223 __netdev_start_xmit include/linux/netdevice.h:4940 [inline] netdev_start_xmit include/linux/netdevice.h:4954 [inline] xmit_one net/core/dev.c:3548 [inline] dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564 __dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349 dev_queue_xmit include/linux/netdevice.h:3134 [inline] packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3087 [inline] packet_sendmsg+0x8b1d/0x9f30 net/packet/af_packet.c:3119 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x735/0xa10 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560 __alloc_skb+0x318/0x740 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2787 packet_alloc_skb net/packet/af_packet.c:2936 [inline] packet_snd net/packet/af_packet.c:3030 [inline] packet_sendmsg+0x70e8/0x9f30 net/packet/af_packet.c:3119 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x735/0xa10 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 1 PID: 5033 Comm: syz-executor334 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 ===================================================== If the packet type ID field in the Ethernet header is either ETH_P_PRP or ETH_P_HSR, but it is not followed by an HSR tag, hsr_get_skb_sequence_nr() reads an invalid value as a sequence number. This causes the above issue. This patch fixes the issue by returning NULL if the Ethernet header is not followed by an HSR tag. | |||||
| CVE-2024-26771 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-01-27 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: dmaengine: ti: edma: Add some null pointer checks to the edma_probe devm_kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. Ensure the allocation was successful by checking the pointer validity. | |||||
| CVE-2024-26770 | 1 Linux | 1 Linux Kernel | 2025-01-27 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: HID: nvidia-shield: Add missing null pointer checks to LED initialization devm_kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. Ensure the allocation was successful by checking the pointer validity. [jkosina@suse.com: tweak changelog a bit] | |||||
| CVE-2024-26649 | 1 Linux | 1 Linux Kernel | 2025-01-27 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix the null pointer when load rlc firmware If the RLC firmware is invalid because of wrong header size, the pointer to the rlc firmware is released in function amdgpu_ucode_request. There will be a null pointer error in subsequent use. So skip validation to fix it. | |||||
| CVE-2024-49926 | 1 Linux | 1 Linux Kernel | 2025-01-24 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: rcu-tasks: Fix access non-existent percpu rtpcp variable in rcu_tasks_need_gpcb() For kernels built with CONFIG_FORCE_NR_CPUS=y, the nr_cpu_ids is defined as NR_CPUS instead of the number of possible cpus, this will cause the following system panic: smpboot: Allowing 4 CPUs, 0 hotplug CPUs ... setup_percpu: NR_CPUS:512 nr_cpumask_bits:512 nr_cpu_ids:512 nr_node_ids:1 ... BUG: unable to handle page fault for address: ffffffff9911c8c8 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 15 Comm: rcu_tasks_trace Tainted: G W 6.6.21 #1 5dc7acf91a5e8e9ac9dcfc35bee0245691283ea6 RIP: 0010:rcu_tasks_need_gpcb+0x25d/0x2c0 RSP: 0018:ffffa371c00a3e60 EFLAGS: 00010082 CR2: ffffffff9911c8c8 CR3: 000000040fa20005 CR4: 00000000001706f0 Call Trace: <TASK> ? __die+0x23/0x80 ? page_fault_oops+0xa4/0x180 ? exc_page_fault+0x152/0x180 ? asm_exc_page_fault+0x26/0x40 ? rcu_tasks_need_gpcb+0x25d/0x2c0 ? __pfx_rcu_tasks_kthread+0x40/0x40 rcu_tasks_one_gp+0x69/0x180 rcu_tasks_kthread+0x94/0xc0 kthread+0xe8/0x140 ? __pfx_kthread+0x40/0x40 ret_from_fork+0x34/0x80 ? __pfx_kthread+0x40/0x40 ret_from_fork_asm+0x1b/0x80 </TASK> Considering that there may be holes in the CPU numbers, use the maximum possible cpu number, instead of nr_cpu_ids, for configuring enqueue and dequeue limits. [ neeraj.upadhyay: Fix htmldocs build error reported by Stephen Rothwell ] | |||||
| CVE-2024-42067 | 1 Linux | 1 Linux Kernel | 2025-01-24 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: bpf: Take return from set_memory_rox() into account with bpf_jit_binary_lock_ro() set_memory_rox() can fail, leaving memory unprotected. Check return and bail out when bpf_jit_binary_lock_ro() returns an error. | |||||
| CVE-2024-26885 | 1 Linux | 1 Linux Kernel | 2025-01-24 | N/A | 7.8 HIGH |
| In the Linux kernel, the following vulnerability has been resolved: bpf: Fix DEVMAP_HASH overflow check on 32-bit arches The devmap code allocates a number hash buckets equal to the next power of two of the max_entries value provided when creating the map. When rounding up to the next power of two, the 32-bit variable storing the number of buckets can overflow, and the code checks for overflow by checking if the truncated 32-bit value is equal to 0. However, on 32-bit arches the rounding up itself can overflow mid-way through, because it ends up doing a left-shift of 32 bits on an unsigned long value. If the size of an unsigned long is four bytes, this is undefined behaviour, so there is no guarantee that we'll end up with a nice and tidy 0-value at the end. Syzbot managed to turn this into a crash on arm32 by creating a DEVMAP_HASH with max_entries > 0x80000000 and then trying to update it. Fix this by moving the overflow check to before the rounding up operation. | |||||
| CVE-2022-48853 | 1 Linux | 1 Linux Kernel | 2025-01-24 | N/A | 5.5 MEDIUM |
| In the Linux kernel, the following vulnerability has been resolved: swiotlb: fix info leak with DMA_FROM_DEVICE The problem I'm addressing was discovered by the LTP test covering cve-2018-1000204. A short description of what happens follows: 1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device. 2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO. 3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV). 4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer. 5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails. One can argue that this is an swiotlb problem, because without swiotlb we leak all zeros, and the swiotlb should be transparent in a sense that it does not affect the outcome (if all other participants are well behaved). Copying the content of the original buffer into the swiotlb buffer is the only way I can think of to make swiotlb transparent in such scenarios. So let's do just that if in doubt, but allow the driver to tell us that the whole mapped buffer is going to be overwritten, in which case we can preserve the old behavior and avoid the performance impact of the extra bounce. | |||||