Vulnerabilidades

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/damon/sysfs: check contexts-&gt;nr in repeat_call_fn<br /> <br /> damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(),<br /> damon_sysfs_upd_schemes_stats(), and<br /> damon_sysfs_upd_schemes_effective_quotas() without checking contexts-&gt;nr. <br /> If nr_contexts is set to 0 via sysfs while DAMON is running, these<br /> functions dereference contexts_arr[0] and cause a NULL pointer<br /> dereference. Add the missing check.<br /> <br /> For example, the issue can be reproduced using DAMON sysfs interface and<br /> DAMON user-space tool (damo) [1] like below.<br /> <br /> $ sudo damo start --refresh_interval 1s<br /> $ echo 0 | sudo tee \<br /> /sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/damon/sysfs: check contexts-&gt;nr before accessing contexts_arr[0]<br /> <br /> Multiple sysfs command paths dereference contexts_arr[0] without first<br /> verifying that kdamond-&gt;contexts-&gt;nr == 1. A user can set nr_contexts to<br /> 0 via sysfs while DAMON is running, causing NULL pointer dereferences.<br /> <br /> In more detail, the issue can be triggered by privileged users like<br /> below.<br /> <br /> First, start DAMON and make contexts directory empty<br /> (kdamond-&gt;contexts-&gt;nr == 0).<br /> <br /> # damo start<br /> # cd /sys/kernel/mm/damon/admin/kdamonds/0<br /> # echo 0 &gt; contexts/nr_contexts<br /> <br /> Then, each of below commands will cause the NULL pointer dereference.<br /> <br /> # echo update_schemes_stats &gt; state<br /> # echo update_schemes_tried_regions &gt; state<br /> # echo update_schemes_tried_bytes &gt; state<br /> # echo update_schemes_effective_quotas &gt; state<br /> # echo update_tuned_intervals &gt; state<br /> <br /> Guard all commands (except OFF) at the entry point of<br /> damon_sysfs_handle_cmd().

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/damon/sysfs: fix param_ctx leak on damon_sysfs_new_test_ctx() failure<br /> <br /> Patch series "mm/damon/sysfs: fix memory leak and NULL dereference<br /> issues", v4.<br /> <br /> DAMON_SYSFS can leak memory under allocation failure, and do NULL pointer<br /> dereference when a privileged user make wrong sequences of control. Fix<br /> those.<br /> <br /> <br /> This patch (of 3):<br /> <br /> When damon_sysfs_new_test_ctx() fails in damon_sysfs_commit_input(),<br /> param_ctx is leaked because the early return skips the cleanup at the out<br /> label. Destroy param_ctx before returning.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/amdgpu: prevent immediate PASID reuse case<br /> <br /> PASID resue could cause interrupt issue when process<br /> immediately runs into hw state left by previous<br /> process exited with the same PASID, it&amp;#39;s possible that<br /> page faults are still pending in the IH ring buffer when<br /> the process exits and frees up its PASID. To prevent the<br /> case, it uses idr cyclic allocator same as kernel pid&amp;#39;s.<br /> <br /> (cherry picked from commit 8f1de51f49be692de137c8525106e0fce2d1912d)

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/amd/display: Fix drm_edid leak in amdgpu_dm<br /> <br /> [WHAT]<br /> When a sink is connected, aconnector-&gt;drm_edid was overwritten without<br /> freeing the previous allocation, causing a memory leak on resume.<br /> <br /> [HOW]<br /> Free the previous drm_edid before updating it.<br /> <br /> (cherry picked from commit 52024a94e7111366141cfc5d888b2ef011f879e5)

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/amd/display: check if ext_caps is valid in BL setup<br /> <br /> LVDS connectors don&amp;#39;t have extended backlight caps so check<br /> if the pointer is valid before accessing it.<br /> <br /> (cherry picked from commit 3f797396d7f4eb9bb6eded184bbc6f033628a6f6)

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> xfs: stop reclaim before pushing AIL during unmount<br /> <br /> The unmount sequence in xfs_unmount_flush_inodes() pushed the AIL while<br /> background reclaim and inodegc are still running. This is broken<br /> independently of any use-after-free issues - background reclaim and<br /> inodegc should not be running while the AIL is being pushed during<br /> unmount, as inodegc can dirty and insert inodes into the AIL during the<br /> flush, and background reclaim can race to abort and free dirty inodes.<br /> <br /> Reorder xfs_unmount_flush_inodes() to stop inodegc and cancel background<br /> reclaim before pushing the AIL. Stop inodegc before cancelling<br /> m_reclaim_work because the inodegc worker can re-queue m_reclaim_work<br /> via xfs_inodegc_set_reclaimable.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/pagewalk: fix race between concurrent split and refault<br /> <br /> The splitting of a PUD entry in walk_pud_range() can race with a<br /> concurrent thread refaulting the PUD leaf entry causing it to try walking<br /> a PMD range that has disappeared.<br /> <br /> An example and reproduction of this is to try reading numa_maps of a<br /> process while VFIO-PCI is setting up DMA (specifically the<br /> vfio_pin_pages_remote call) on a large BAR for that process.<br /> <br /> This will trigger a kernel BUG:<br /> vfio-pci 0000:03:00.0: enabling device (0000 -&gt; 0002)<br /> BUG: unable to handle page fault for address: ffffa23980000000<br /> PGD 0 P4D 0<br /> Oops: Oops: 0000 [#1] SMP NOPTI<br /> ...<br /> RIP: 0010:walk_pgd_range+0x3b5/0x7a0<br /> Code: 8d 43 ff 48 89 44 24 28 4d 89 ce 4d 8d a7 00 00 20 00 48 8b 4c 24<br /> 28 49 81 e4 00 00 e0 ff 49 8d 44 24 ff 48 39 c8 4c 0f 43 e3 f7 06<br /> 9f ff ff ff 75 3b 48 8b 44 24 20 48 8b 40 28 48 85 c0 74<br /> RSP: 0018:ffffac23e1ecf808 EFLAGS: 00010287<br /> RAX: 00007f44c01fffff RBX: 00007f4500000000 RCX: 00007f44ffffffff<br /> RDX: 0000000000000000 RSI: 000ffffffffff000 RDI: ffffffff93378fe0<br /> RBP: ffffac23e1ecf918 R08: 0000000000000004 R09: ffffa23980000000<br /> R10: 0000000000000020 R11: 0000000000000004 R12: 00007f44c0200000<br /> R13: 00007f44c0000000 R14: ffffa23980000000 R15: 00007f44c0000000<br /> FS: 00007fe884739580(0000) GS:ffff9b7d7a9c0000(0000)<br /> knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: ffffa23980000000 CR3: 000000c0650e2005 CR4: 0000000000770ef0<br /> PKRU: 55555554<br /> Call Trace:<br /> <br /> __walk_page_range+0x195/0x1b0<br /> walk_page_vma+0x62/0xc0<br /> show_numa_map+0x12b/0x3b0<br /> seq_read_iter+0x297/0x440<br /> seq_read+0x11d/0x140<br /> vfs_read+0xc2/0x340<br /> ksys_read+0x5f/0xe0<br /> do_syscall_64+0x68/0x130<br /> ? get_page_from_freelist+0x5c2/0x17e0<br /> ? mas_store_prealloc+0x17e/0x360<br /> ? vma_set_page_prot+0x4c/0xa0<br /> ? __alloc_pages_noprof+0x14e/0x2d0<br /> ? __mod_memcg_lruvec_state+0x8d/0x140<br /> ? __lruvec_stat_mod_folio+0x76/0xb0<br /> ? __folio_mod_stat+0x26/0x80<br /> ? do_anonymous_page+0x705/0x900<br /> ? __handle_mm_fault+0xa8d/0x1000<br /> ? __count_memcg_events+0x53/0xf0<br /> ? handle_mm_fault+0xa5/0x360<br /> ? do_user_addr_fault+0x342/0x640<br /> ? arch_exit_to_user_mode_prepare.constprop.0+0x16/0xa0<br /> ? irqentry_exit_to_user_mode+0x24/0x100<br /> entry_SYSCALL_64_after_hwframe+0x76/0x7e<br /> RIP: 0033:0x7fe88464f47e<br /> Code: c0 e9 b6 fe ff ff 50 48 8d 3d be 07 0b 00 e8 69 01 02 00 66 0f 1f<br /> 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 3d 00<br /> f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28<br /> RSP: 002b:00007ffe6cd9a9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000<br /> RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fe88464f47e<br /> RDX: 0000000000020000 RSI: 00007fe884543000 RDI: 0000000000000003<br /> RBP: 00007fe884543000 R08: 00007fe884542010 R09: 0000000000000000<br /> R10: fffffffffffffbc5 R11: 0000000000000246 R12: 0000000000000000<br /> R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000<br /> <br /> <br /> Fix this by validating the PUD entry in walk_pmd_range() using a stable<br /> snapshot (pudp_get()). If the PUD is not present or is a leaf, retry the<br /> walk via ACTION_AGAIN instead of descending further. This mirrors the<br /> retry logic in walk_pte_range(), which lets walk_pmd_range() retry if the<br /> PTE is not being got by pte_offset_map_lock().

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> xfs: avoid dereferencing log items after push callbacks<br /> <br /> After xfsaild_push_item() calls iop_push(), the log item may have been<br /> freed if the AIL lock was dropped during the push. Background inode<br /> reclaim or the dquot shrinker can free the log item while the AIL lock<br /> is not held, and the tracepoints in the switch statement dereference<br /> the log item after iop_push() returns.<br /> <br /> Fix this by capturing the log item type, flags, and LSN before calling<br /> xfsaild_push_item(), and introducing a new xfs_ail_push_class trace<br /> event class that takes these pre-captured values and the ailp pointer<br /> instead of the log item pointer.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> xfs: save ailp before dropping the AIL lock in push callbacks<br /> <br /> In xfs_inode_item_push() and xfs_qm_dquot_logitem_push(), the AIL lock<br /> is dropped to perform buffer IO. Once the cluster buffer no longer<br /> protects the log item from reclaim, the log item may be freed by<br /> background reclaim or the dquot shrinker. The subsequent spin_lock()<br /> call dereferences lip-&gt;li_ailp, which is a use-after-free.<br /> <br /> Fix this by saving the ailp pointer in a local variable while the AIL<br /> lock is held and the log item is guaranteed to be valid.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ext4: publish jinode after initialization<br /> <br /> ext4_inode_attach_jinode() publishes ei-&gt;jinode to concurrent users.<br /> It used to set ei-&gt;jinode before jbd2_journal_init_jbd_inode(),<br /> allowing a reader to observe a non-NULL jinode with i_vfs_inode<br /> still unset.<br /> <br /> The fast commit flush path can then pass this jinode to<br /> jbd2_wait_inode_data(), which dereferences i_vfs_inode-&gt;i_mapping and<br /> may crash.<br /> <br /> Below is the crash I observe:<br /> ```<br /> BUG: unable to handle page fault for address: 000000010beb47f4<br /> PGD 110e51067 P4D 110e51067 PUD 0<br /> Oops: Oops: 0000 [#1] SMP NOPTI<br /> CPU: 1 UID: 0 PID: 4850 Comm: fc_fsync_bench_ Not tainted 6.18.0-00764-g795a690c06a5 #1 PREEMPT(voluntary)<br /> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014<br /> RIP: 0010:xas_find_marked+0x3d/0x2e0<br /> Code: e0 03 48 83 f8 02 0f 84 f0 01 00 00 48 8b 47 08 48 89 c3 48 39 c6 0f 82 fd 01 00 00 48 85 c9 74 3d 48 83 f9 03 77 63 4c 8b 0f 8b 71 08 48 c7 47 18 00 00 00 00 48 89 f1 83 e1 03 48 83 f9 02<br /> RSP: 0018:ffffbbee806e7bf0 EFLAGS: 00010246<br /> RAX: 000000000010beb4 RBX: 000000000010beb4 RCX: 0000000000000003<br /> RDX: 0000000000000001 RSI: 0000002000300000 RDI: ffffbbee806e7c10<br /> RBP: 0000000000000001 R08: 0000002000300000 R09: 000000010beb47ec<br /> R10: ffff9ea494590090 R11: 0000000000000000 R12: 0000002000300000<br /> R13: ffffbbee806e7c90 R14: ffff9ea494513788 R15: ffffbbee806e7c88<br /> FS: 00007fc2f9e3e6c0(0000) GS:ffff9ea6b1444000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 000000010beb47f4 CR3: 0000000119ac5000 CR4: 0000000000750ef0<br /> PKRU: 55555554<br /> Call Trace:<br /> <br /> filemap_get_folios_tag+0x87/0x2a0<br /> __filemap_fdatawait_range+0x5f/0xd0<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> ? __schedule+0x3e7/0x10c0<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> ? preempt_count_sub+0x5f/0x80<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> ? cap_safe_nice+0x37/0x70<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> ? preempt_count_sub+0x5f/0x80<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> filemap_fdatawait_range_keep_errors+0x12/0x40<br /> ext4_fc_commit+0x697/0x8b0<br /> ? ext4_file_write_iter+0x64b/0x950<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> ? preempt_count_sub+0x5f/0x80<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> ? vfs_write+0x356/0x480<br /> ? srso_alias_return_thunk+0x5/0xfbef5<br /> ? preempt_count_sub+0x5f/0x80<br /> ext4_sync_file+0xf7/0x370<br /> do_fsync+0x3b/0x80<br /> ? syscall_trace_enter+0x108/0x1d0<br /> __x64_sys_fdatasync+0x16/0x20<br /> do_syscall_64+0x62/0x2c0<br /> entry_SYSCALL_64_after_hwframe+0x76/0x7e<br /> ...<br /> ```<br /> <br /> Fix this by initializing the jbd2_inode first.<br /> Use smp_wmb() and WRITE_ONCE() to publish ei-&gt;jinode after<br /> initialization. Readers use READ_ONCE() to fetch the pointer.

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ext4: replace BUG_ON with proper error handling in ext4_read_inline_folio<br /> <br /> Replace BUG_ON() with proper error handling when inline data size<br /> exceeds PAGE_SIZE. This prevents kernel panic and allows the system to<br /> continue running while properly reporting the filesystem corruption.<br /> <br /> The error is logged via ext4_error_inode(), the buffer head is released<br /> to prevent memory leak, and -EFSCORRUPTED is returned to indicate<br /> filesystem corruption.