Total
297 CVE
| CVE | Vendors | Products | Updated | CVSS v3.1 |
|---|---|---|---|---|
| CVE-2024-41007 | 2 Linux, Redhat | 3 Linux Kernel, Enterprise Linux, Rhel Eus | 2024-12-19 | 3.3 Low |
| In the Linux kernel, the following vulnerability has been resolved: tcp: avoid too many retransmit packets If a TCP socket is using TCP_USER_TIMEOUT, and the other peer retracted its window to zero, tcp_retransmit_timer() can retransmit a packet every two jiffies (2 ms for HZ=1000), for about 4 minutes after TCP_USER_TIMEOUT has 'expired'. The fix is to make sure tcp_rtx_probe0_timed_out() takes icsk->icsk_user_timeout into account. Before blamed commit, the socket would not timeout after icsk->icsk_user_timeout, but would use standard exponential backoff for the retransmits. Also worth noting that before commit e89688e3e978 ("net: tcp: fix unexcepted socket die when snd_wnd is 0"), the issue would last 2 minutes instead of 4. | ||||
| CVE-2024-41003 | 2024-12-19 | 4.4 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: bpf: Fix reg_set_min_max corruption of fake_reg Juan reported that after doing some changes to buzzer [0] and implementing a new fuzzing strategy guided by coverage, they noticed the following in one of the probes: [...] 13: (79) r6 = *(u64 *)(r0 +0) ; R0=map_value(ks=4,vs=8) R6_w=scalar() 14: (b7) r0 = 0 ; R0_w=0 15: (b4) w0 = -1 ; R0_w=0xffffffff 16: (74) w0 >>= 1 ; R0_w=0x7fffffff 17: (5c) w6 &= w0 ; R0_w=0x7fffffff R6_w=scalar(smin=smin32=0,smax=umax=umax32=0x7fffffff,var_off=(0x0; 0x7fffffff)) 18: (44) w6 |= 2 ; R6_w=scalar(smin=umin=smin32=umin32=2,smax=umax=umax32=0x7fffffff,var_off=(0x2; 0x7ffffffd)) 19: (56) if w6 != 0x7ffffffd goto pc+1 REG INVARIANTS VIOLATION (true_reg2): range bounds violation u64=[0x7fffffff, 0x7ffffffd] s64=[0x7fffffff, 0x7ffffffd] u32=[0x7fffffff, 0x7ffffffd] s32=[0x7fffffff, 0x7ffffffd] var_off=(0x7fffffff, 0x0) REG INVARIANTS VIOLATION (false_reg1): range bounds violation u64=[0x7fffffff, 0x7ffffffd] s64=[0x7fffffff, 0x7ffffffd] u32=[0x7fffffff, 0x7ffffffd] s32=[0x7fffffff, 0x7ffffffd] var_off=(0x7fffffff, 0x0) REG INVARIANTS VIOLATION (false_reg2): const tnum out of sync with range bounds u64=[0x0, 0xffffffffffffffff] s64=[0x8000000000000000, 0x7fffffffffffffff] u32=[0x0, 0xffffffff] s32=[0x80000000, 0x7fffffff] var_off=(0x7fffffff, 0x0) 19: R6_w=0x7fffffff 20: (95) exit from 19 to 21: R0=0x7fffffff R6=scalar(smin=umin=smin32=umin32=2,smax=umax=smax32=umax32=0x7ffffffe,var_off=(0x2; 0x7ffffffd)) R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm 21: R0=0x7fffffff R6=scalar(smin=umin=smin32=umin32=2,smax=umax=smax32=umax32=0x7ffffffe,var_off=(0x2; 0x7ffffffd)) R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm 21: (14) w6 -= 2147483632 ; R6_w=scalar(smin=umin=umin32=2,smax=umax=0xffffffff,smin32=0x80000012,smax32=14,var_off=(0x2; 0xfffffffd)) 22: (76) if w6 s>= 0xe goto pc+1 ; R6_w=scalar(smin=umin=umin32=2,smax=umax=0xffffffff,smin32=0x80000012,smax32=13,var_off=(0x2; 0xfffffffd)) 23: (95) exit from 22 to 24: R0=0x7fffffff R6_w=14 R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm 24: R0=0x7fffffff R6_w=14 R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm 24: (14) w6 -= 14 ; R6_w=0 [...] What can be seen here is a register invariant violation on line 19. After the binary-or in line 18, the verifier knows that bit 2 is set but knows nothing about the rest of the content which was loaded from a map value, meaning, range is [2,0x7fffffff] with var_off=(0x2; 0x7ffffffd). When in line 19 the verifier analyzes the branch, it splits the register states in reg_set_min_max() into the registers of the true branch (true_reg1, true_reg2) and the registers of the false branch (false_reg1, false_reg2). Since the test is w6 != 0x7ffffffd, the src_reg is a known constant. Internally, the verifier creates a "fake" register initialized as scalar to the value of 0x7ffffffd, and then passes it onto reg_set_min_max(). Now, for line 19, it is mathematically impossible to take the false branch of this program, yet the verifier analyzes it. It is impossible because the second bit of r6 will be set due to the prior or operation and the constant in the condition has that bit unset (hex(fd) == binary(1111 1101). When the verifier first analyzes the false / fall-through branch, it will compute an intersection between the var_off of r6 and of the constant. This is because the verifier creates a "fake" register initialized to the value of the constant. The intersection result later refines both registers in regs_refine_cond_op(): [...] t = tnum_intersect(tnum_subreg(reg1->var_off), tnum_subreg(reg2->var_off)); reg1->var_o ---truncated--- | ||||
| CVE-2024-40999 | 2024-12-19 | 4.4 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: net: ena: Add validation for completion descriptors consistency Validate that `first` flag is set only for the first descriptor in multi-buffer packets. In case of an invalid descriptor, a reset will occur. A new reset reason for RX data corruption has been added. | ||||
| CVE-2024-40993 | 2024-12-19 | 5.5 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: Fix suspicious rcu_dereference_protected() When destroying all sets, we are either in pernet exit phase or are executing a "destroy all sets command" from userspace. The latter was taken into account in ip_set_dereference() (nfnetlink mutex is held), but the former was not. The patch adds the required check to rcu_dereference_protected() in ip_set_dereference(). | ||||
| CVE-2024-40968 | 2024-12-19 | 4.4 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: MIPS: Octeon: Add PCIe link status check The standard PCIe configuration read-write interface is used to access the configuration space of the peripheral PCIe devices of the mips processor after the PCIe link surprise down, it can generate kernel panic caused by "Data bus error". So it is necessary to add PCIe link status check for system protection. When the PCIe link is down or in training, assigning a value of 0 to the configuration address can prevent read-write behavior to the configuration space of peripheral PCIe devices, thereby preventing kernel panic. | ||||
| CVE-2024-40966 | 1 Redhat | 1 Enterprise Linux | 2024-12-19 | 4.4 Medium |
| In the Linux kernel, the following vulnerability has been resolved: tty: add the option to have a tty reject a new ldisc ... and use it to limit the virtual terminals to just N_TTY. They are kind of special, and in particular, the "con_write()" routine violates the "writes cannot sleep" rule that some ldiscs rely on. This avoids the BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659 when N_GSM has been attached to a virtual console, and gsmld_write() calls con_write() while holding a spinlock, and con_write() then tries to get the console lock. | ||||
| CVE-2024-40963 | 2024-12-19 | 4.4 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: mips: bmips: BCM6358: make sure CBR is correctly set It was discovered that some device have CBR address set to 0 causing kernel panic when arch_sync_dma_for_cpu_all is called. This was notice in situation where the system is booted from TP1 and BMIPS_GET_CBR() returns 0 instead of a valid address and !!(read_c0_brcm_cmt_local() & (1 << 31)); not failing. The current check whether RAC flush should be disabled or not are not enough hence lets check if CBR is a valid address or not. | ||||
| CVE-2024-40950 | 2024-12-19 | 5.5 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: mm: huge_memory: fix misused mapping_large_folio_support() for anon folios When I did a large folios split test, a WARNING "[ 5059.122759][ T166] Cannot split file folio to non-0 order" was triggered. But the test cases are only for anonmous folios. while mapping_large_folio_support() is only reasonable for page cache folios. In split_huge_page_to_list_to_order(), the folio passed to mapping_large_folio_support() maybe anonmous folio. The folio_test_anon() check is missing. So the split of the anonmous THP is failed. This is also the same for shmem_mapping(). We'd better add a check for both. But the shmem_mapping() in __split_huge_page() is not involved, as for anonmous folios, the end parameter is set to -1, so (head[i].index >= end) is always false. shmem_mapping() is not called. Also add a VM_WARN_ON_ONCE() in mapping_large_folio_support() for anon mapping, So we can detect the wrong use more easily. THP folios maybe exist in the pagecache even the file system doesn't support large folio, it is because when CONFIG_TRANSPARENT_HUGEPAGE is enabled, khugepaged will try to collapse read-only file-backed pages to THP. But the mapping does not actually support multi order large folios properly. Using /sys/kernel/debug/split_huge_pages to verify this, with this patch, large anon THP is successfully split and the warning is ceased. | ||||
| CVE-2024-40949 | 2024-12-19 | 5.5 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: mm: shmem: fix getting incorrect lruvec when replacing a shmem folio When testing shmem swapin, I encountered the warning below on my machine. The reason is that replacing an old shmem folio with a new one causes mem_cgroup_migrate() to clear the old folio's memcg data. As a result, the old folio cannot get the correct memcg's lruvec needed to remove itself from the LRU list when it is being freed. This could lead to possible serious problems, such as LRU list crashes due to holding the wrong LRU lock, and incorrect LRU statistics. To fix this issue, we can fallback to use the mem_cgroup_replace_folio() to replace the old shmem folio. [ 5241.100311] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d9960 [ 5241.100317] head: order:4 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 [ 5241.100319] flags: 0x17fffe0000040068(uptodate|lru|head|swapbacked|node=0|zone=2|lastcpupid=0x3ffff) [ 5241.100323] raw: 17fffe0000040068 fffffdffd6687948 fffffdffd69ae008 0000000000000000 [ 5241.100325] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 5241.100326] head: 17fffe0000040068 fffffdffd6687948 fffffdffd69ae008 0000000000000000 [ 5241.100327] head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 5241.100328] head: 17fffe0000000204 fffffdffd6665801 ffffffffffffffff 0000000000000000 [ 5241.100329] head: 0000000a00000010 0000000000000000 00000000ffffffff 0000000000000000 [ 5241.100330] page dumped because: VM_WARN_ON_ONCE_FOLIO(!memcg && !mem_cgroup_disabled()) [ 5241.100338] ------------[ cut here ]------------ [ 5241.100339] WARNING: CPU: 19 PID: 78402 at include/linux/memcontrol.h:775 folio_lruvec_lock_irqsave+0x140/0x150 [...] [ 5241.100374] pc : folio_lruvec_lock_irqsave+0x140/0x150 [ 5241.100375] lr : folio_lruvec_lock_irqsave+0x138/0x150 [ 5241.100376] sp : ffff80008b38b930 [...] [ 5241.100398] Call trace: [ 5241.100399] folio_lruvec_lock_irqsave+0x140/0x150 [ 5241.100401] __page_cache_release+0x90/0x300 [ 5241.100404] __folio_put+0x50/0x108 [ 5241.100406] shmem_replace_folio+0x1b4/0x240 [ 5241.100409] shmem_swapin_folio+0x314/0x528 [ 5241.100411] shmem_get_folio_gfp+0x3b4/0x930 [ 5241.100412] shmem_fault+0x74/0x160 [ 5241.100414] __do_fault+0x40/0x218 [ 5241.100417] do_shared_fault+0x34/0x1b0 [ 5241.100419] do_fault+0x40/0x168 [ 5241.100420] handle_pte_fault+0x80/0x228 [ 5241.100422] __handle_mm_fault+0x1c4/0x440 [ 5241.100424] handle_mm_fault+0x60/0x1f0 [ 5241.100426] do_page_fault+0x120/0x488 [ 5241.100429] do_translation_fault+0x4c/0x68 [ 5241.100431] do_mem_abort+0x48/0xa0 [ 5241.100434] el0_da+0x38/0xc0 [ 5241.100436] el0t_64_sync_handler+0x68/0xc0 [ 5241.100437] el0t_64_sync+0x14c/0x150 [ 5241.100439] ---[ end trace 0000000000000000 ]--- [baolin.wang@linux.alibaba.com: remove less helpful comments, per Matthew] Link: https://lkml.kernel.org/r/ccad3fe1375b468ebca3227b6b729f3eaf9d8046.1718423197.git.baolin.wang@linux.alibaba.com | ||||
| CVE-2024-40948 | 1 Redhat | 1 Enterprise Linux | 2024-12-19 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: mm/page_table_check: fix crash on ZONE_DEVICE Not all pages may apply to pgtable check. One example is ZONE_DEVICE pages: they map PFNs directly, and they don't allocate page_ext at all even if there's struct page around. One may reference devm_memremap_pages(). When both ZONE_DEVICE and page-table-check enabled, then try to map some dax memories, one can trigger kernel bug constantly now when the kernel was trying to inject some pfn maps on the dax device: kernel BUG at mm/page_table_check.c:55! While it's pretty legal to use set_pxx_at() for ZONE_DEVICE pages for page fault resolutions, skip all the checks if page_ext doesn't even exist in pgtable checker, which applies to ZONE_DEVICE but maybe more. | ||||
| CVE-2024-40940 | 1 Redhat | 1 Enterprise Linux | 2024-12-19 | 4.4 Medium |
| In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Fix tainted pointer delete is case of flow rules creation fail In case of flow rule creation fail in mlx5_lag_create_port_sel_table(), instead of previously created rules, the tainted pointer is deleted deveral times. Fix this bug by using correct flow rules pointers. Found by Linux Verification Center (linuxtesting.org) with SVACE. | ||||
| CVE-2024-40939 | 1 Redhat | 1 Enterprise Linux | 2024-12-19 | 4.4 Medium |
| In the Linux kernel, the following vulnerability has been resolved: net: wwan: iosm: Fix tainted pointer delete is case of region creation fail In case of region creation fail in ipc_devlink_create_region(), previously created regions delete process starts from tainted pointer which actually holds error code value. Fix this bug by decreasing region index before delete. Found by Linux Verification Center (linuxtesting.org) with SVACE. | ||||
| CVE-2024-40938 | 2024-12-19 | 5.5 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: landlock: Fix d_parent walk The WARN_ON_ONCE() in collect_domain_accesses() can be triggered when trying to link a root mount point. This cannot work in practice because this directory is mounted, but the VFS check is done after the call to security_path_link(). Do not use source directory's d_parent when the source directory is the mount point. [mic: Fix commit message] | ||||
| CVE-2024-40935 | 2024-12-19 | 5.5 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: cachefiles: flush all requests after setting CACHEFILES_DEAD In ondemand mode, when the daemon is processing an open request, if the kernel flags the cache as CACHEFILES_DEAD, the cachefiles_daemon_write() will always return -EIO, so the daemon can't pass the copen to the kernel. Then the kernel process that is waiting for the copen triggers a hung_task. Since the DEAD state is irreversible, it can only be exited by closing /dev/cachefiles. Therefore, after calling cachefiles_io_error() to mark the cache as CACHEFILES_DEAD, if in ondemand mode, flush all requests to avoid the above hungtask. We may still be able to read some of the cached data before closing the fd of /dev/cachefiles. Note that this relies on the patch that adds reference counting to the req, otherwise it may UAF. | ||||
| CVE-2024-40924 | 1 Redhat | 2 Enterprise Linux, Rhel Eus | 2024-12-19 | 4.4 Medium |
| In the Linux kernel, the following vulnerability has been resolved: drm/i915/dpt: Make DPT object unshrinkable In some scenarios, the DPT object gets shrunk but the actual framebuffer did not and thus its still there on the DPT's vm->bound_list. Then it tries to rewrite the PTEs via a stale CPU mapping. This causes panic. [vsyrjala: Add TODO comment] (cherry picked from commit 51064d471c53dcc8eddd2333c3f1c1d9131ba36c) | ||||
| CVE-2024-40923 | 1 Redhat | 1 Enterprise Linux | 2024-12-19 | 4.4 Medium |
| In the Linux kernel, the following vulnerability has been resolved: vmxnet3: disable rx data ring on dma allocation failure When vmxnet3_rq_create() fails to allocate memory for rq->data_ring.base, the subsequent call to vmxnet3_rq_destroy_all_rxdataring does not reset rq->data_ring.desc_size for the data ring that failed, which presumably causes the hypervisor to reference it on packet reception. To fix this bug, rq->data_ring.desc_size needs to be set to 0 to tell the hypervisor to disable this feature. [ 95.436876] kernel BUG at net/core/skbuff.c:207! [ 95.439074] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 95.440411] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 6.9.3-dirty #1 [ 95.441558] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 12/12/2018 [ 95.443481] RIP: 0010:skb_panic+0x4d/0x4f [ 95.444404] Code: 4f 70 50 8b 87 c0 00 00 00 50 8b 87 bc 00 00 00 50 ff b7 d0 00 00 00 4c 8b 8f c8 00 00 00 48 c7 c7 68 e8 be 9f e8 63 58 f9 ff <0f> 0b 48 8b 14 24 48 c7 c1 d0 73 65 9f e8 a1 ff ff ff 48 8b 14 24 [ 95.447684] RSP: 0018:ffffa13340274dd0 EFLAGS: 00010246 [ 95.448762] RAX: 0000000000000089 RBX: ffff8fbbc72b02d0 RCX: 000000000000083f [ 95.450148] RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f [ 95.451520] RBP: 000000000000002d R08: 0000000000000000 R09: ffffa13340274c60 [ 95.452886] R10: ffffffffa04ed468 R11: 0000000000000002 R12: 0000000000000000 [ 95.454293] R13: ffff8fbbdab3c2d0 R14: ffff8fbbdbd829e0 R15: ffff8fbbdbd809e0 [ 95.455682] FS: 0000000000000000(0000) GS:ffff8fbeefd80000(0000) knlGS:0000000000000000 [ 95.457178] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 95.458340] CR2: 00007fd0d1f650c8 CR3: 0000000115f28000 CR4: 00000000000406f0 [ 95.459791] Call Trace: [ 95.460515] <IRQ> [ 95.461180] ? __die_body.cold+0x19/0x27 [ 95.462150] ? die+0x2e/0x50 [ 95.462976] ? do_trap+0xca/0x110 [ 95.463973] ? do_error_trap+0x6a/0x90 [ 95.464966] ? skb_panic+0x4d/0x4f [ 95.465901] ? exc_invalid_op+0x50/0x70 [ 95.466849] ? skb_panic+0x4d/0x4f [ 95.467718] ? asm_exc_invalid_op+0x1a/0x20 [ 95.468758] ? skb_panic+0x4d/0x4f [ 95.469655] skb_put.cold+0x10/0x10 [ 95.470573] vmxnet3_rq_rx_complete+0x862/0x11e0 [vmxnet3] [ 95.471853] vmxnet3_poll_rx_only+0x36/0xb0 [vmxnet3] [ 95.473185] __napi_poll+0x2b/0x160 [ 95.474145] net_rx_action+0x2c6/0x3b0 [ 95.475115] handle_softirqs+0xe7/0x2a0 [ 95.476122] __irq_exit_rcu+0x97/0xb0 [ 95.477109] common_interrupt+0x85/0xa0 [ 95.478102] </IRQ> [ 95.478846] <TASK> [ 95.479603] asm_common_interrupt+0x26/0x40 [ 95.480657] RIP: 0010:pv_native_safe_halt+0xf/0x20 [ 95.481801] Code: 22 d7 e9 54 87 01 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 93 ba 3b 00 fb f4 <e9> 2c 87 01 00 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 [ 95.485563] RSP: 0018:ffffa133400ffe58 EFLAGS: 00000246 [ 95.486882] RAX: 0000000000004000 RBX: ffff8fbbc1d14064 RCX: 0000000000000000 [ 95.488477] RDX: ffff8fbeefd80000 RSI: ffff8fbbc1d14000 RDI: 0000000000000001 [ 95.490067] RBP: ffff8fbbc1d14064 R08: ffffffffa0652260 R09: 00000000000010d3 [ 95.491683] R10: 0000000000000018 R11: ffff8fbeefdb4764 R12: ffffffffa0652260 [ 95.493389] R13: ffffffffa06522e0 R14: 0000000000000001 R15: 0000000000000000 [ 95.495035] acpi_safe_halt+0x14/0x20 [ 95.496127] acpi_idle_do_entry+0x2f/0x50 [ 95.497221] acpi_idle_enter+0x7f/0xd0 [ 95.498272] cpuidle_enter_state+0x81/0x420 [ 95.499375] cpuidle_enter+0x2d/0x40 [ 95.500400] do_idle+0x1e5/0x240 [ 95.501385] cpu_startup_entry+0x29/0x30 [ 95.502422] start_secondary+0x11c/0x140 [ 95.503454] common_startup_64+0x13e/0x141 [ 95.504466] </TASK> [ 95.505197] Modules linked in: nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ip ---truncated--- | ||||
| CVE-2024-40921 | 2024-12-19 | 5.5 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: net: bridge: mst: pass vlan group directly to br_mst_vlan_set_state Pass the already obtained vlan group pointer to br_mst_vlan_set_state() instead of dereferencing it again. Each caller has already correctly dereferenced it for their context. This change is required for the following suspicious RCU dereference fix. No functional changes intended. | ||||
| CVE-2024-40918 | 2024-12-19 | 4.4 Medium | ||
| In the Linux kernel, the following vulnerability has been resolved: parisc: Try to fix random segmentation faults in package builds PA-RISC systems with PA8800 and PA8900 processors have had problems with random segmentation faults for many years. Systems with earlier processors are much more stable. Systems with PA8800 and PA8900 processors have a large L2 cache which needs per page flushing for decent performance when a large range is flushed. The combined cache in these systems is also more sensitive to non-equivalent aliases than the caches in earlier systems. The majority of random segmentation faults that I have looked at appear to be memory corruption in memory allocated using mmap and malloc. My first attempt at fixing the random faults didn't work. On reviewing the cache code, I realized that there were two issues which the existing code didn't handle correctly. Both relate to cache move-in. Another issue is that the present bit in PTEs is racy. 1) PA-RISC caches have a mind of their own and they can speculatively load data and instructions for a page as long as there is a entry in the TLB for the page which allows move-in. TLBs are local to each CPU. Thus, the TLB entry for a page must be purged before flushing the page. This is particularly important on SMP systems. In some of the flush routines, the flush routine would be called and then the TLB entry would be purged. This was because the flush routine needed the TLB entry to do the flush. 2) My initial approach to trying the fix the random faults was to try and use flush_cache_page_if_present for all flush operations. This actually made things worse and led to a couple of hardware lockups. It finally dawned on me that some lines weren't being flushed because the pte check code was racy. This resulted in random inequivalent mappings to physical pages. The __flush_cache_page tmpalias flush sets up its own TLB entry and it doesn't need the existing TLB entry. As long as we can find the pte pointer for the vm page, we can get the pfn and physical address of the page. We can also purge the TLB entry for the page before doing the flush. Further, __flush_cache_page uses a special TLB entry that inhibits cache move-in. When switching page mappings, we need to ensure that lines are removed from the cache. It is not sufficient to just flush the lines to memory as they may come back. This made it clear that we needed to implement all the required flush operations using tmpalias routines. This includes flushes for user and kernel pages. After modifying the code to use tmpalias flushes, it became clear that the random segmentation faults were not fully resolved. The frequency of faults was worse on systems with a 64 MB L2 (PA8900) and systems with more CPUs (rp4440). The warning that I added to flush_cache_page_if_present to detect pages that couldn't be flushed triggered frequently on some systems. Helge and I looked at the pages that couldn't be flushed and found that the PTE was either cleared or for a swap page. Ignoring pages that were swapped out seemed okay but pages with cleared PTEs seemed problematic. I looked at routines related to pte_clear and noticed ptep_clear_flush. The default implementation just flushes the TLB entry. However, it was obvious that on parisc we need to flush the cache page as well. If we don't flush the cache page, stale lines will be left in the cache and cause random corruption. Once a PTE is cleared, there is no way to find the physical address associated with the PTE and flush the associated page at a later time. I implemented an updated change with a parisc specific version of ptep_clear_flush. It fixed the random data corruption on Helge's rp4440 and rp3440, as well as on my c8000. At this point, I realized that I could restore the code where we only flush in flush_cache_page_if_present if the page has been accessed. However, for this, we also need to flush the cache when the accessed bit is cleared in ---truncated--- | ||||
| CVE-2024-39483 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2024-12-19 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: WARN on vNMI + NMI window iff NMIs are outright masked When requesting an NMI window, WARN on vNMI support being enabled if and only if NMIs are actually masked, i.e. if the vCPU is already handling an NMI. KVM's ABI for NMIs that arrive simultanesouly (from KVM's point of view) is to inject one NMI and pend the other. When using vNMI, KVM pends the second NMI simply by setting V_NMI_PENDING, and lets the CPU do the rest (hardware automatically sets V_NMI_BLOCKING when an NMI is injected). However, if KVM can't immediately inject an NMI, e.g. because the vCPU is in an STI shadow or is running with GIF=0, then KVM will request an NMI window and trigger the WARN (but still function correctly). Whether or not the GIF=0 case makes sense is debatable, as the intent of KVM's behavior is to provide functionality that is as close to real hardware as possible. E.g. if two NMIs are sent in quick succession, the probability of both NMIs arriving in an STI shadow is infinitesimally low on real hardware, but significantly larger in a virtual environment, e.g. if the vCPU is preempted in the STI shadow. For GIF=0, the argument isn't as clear cut, because the window where two NMIs can collide is much larger in bare metal (though still small). That said, KVM should not have divergent behavior for the GIF=0 case based on whether or not vNMI support is enabled. And KVM has allowed simultaneous NMIs with GIF=0 for over a decade, since commit 7460fb4a3400 ("KVM: Fix simultaneous NMIs"). I.e. KVM's GIF=0 handling shouldn't be modified without a *really* good reason to do so, and if KVM's behavior were to be modified, it should be done irrespective of vNMI support. | ||||
| CVE-2024-39481 | 1 Linux | 1 Linux Kernel | 2024-12-19 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: media: mc: Fix graph walk in media_pipeline_start The graph walk tries to follow all links, even if they are not between pads. This causes a crash with, e.g. a MEDIA_LNK_FL_ANCILLARY_LINK link. Fix this by allowing the walk to proceed only for MEDIA_LNK_FL_DATA_LINK links. | ||||