CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2024-39293 – Revert "xsk: Support redirect to any socket bound to the same umem"
https://notcve.org/view.php?id=CVE-2024-39293
In the Linux kernel, the following vulnerability has been resolved: Revert "xsk: Support redirect to any socket bound to the same umem" This reverts commit 2863d665ea41282379f108e4da6c8a2366ba66db. This patch introduced a potential kernel crash when multiple napi instances redirect to the same AF_XDP socket. By removing the queue_index check, it is possible for multiple napi instances to access the Rx ring at the same time, which will result in a corrupted ring state which can lead to a crash when flushing the rings in __xsk_flush(). This can happen when the linked list of sockets to flush gets corrupted by concurrent accesses. A quick and small fix is not possible, so let us revert this for now. • https://git.kernel.org/stable/c/19cb40b1064566ea09538289bfcf5bc7ecb9b6f5 https://git.kernel.org/stable/c/7fcf26b315bbb728036da0862de6b335da83dff2 •
CVSS: 5.5EPSS: 0%CPEs: 10EXPL: 0CVE-2024-39276 – ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find()
https://notcve.org/view.php?id=CVE-2024-39276
In the Linux kernel, the following vulnerability has been resolved: ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() Syzbot reports a warning as follows: ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================ This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage. So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix. • https://git.kernel.org/stable/c/b878c8a7f08f0c225b6a46ba1ac867e9c5d17807 https://git.kernel.org/stable/c/fb265c9cb49e2074ddcdd4de99728aefdd3b3592 https://git.kernel.org/stable/c/9da1f6d06b7a6d068e68fcfd7cbbf6b586d888e1 https://git.kernel.org/stable/c/81313ed2c705d958744882a269bf4a5e3ddec95e https://git.kernel.org/stable/c/9ad75e78747b5a50dc5a52f0f8e92e920a653f16 https://git.kernel.org/stable/c/896a7e7d0d555ad8b2b46af0c2fa7de7467f9483 https://git.kernel.org/stable/c/76dc776153a47372719d664e0fc50d6355791abb https://git.kernel.org/stable/c/681ff9a09accd8a4379f8bd30b7a1641e • CWE-402: Transmission of Private Resources into a New Sphere ('Resource Leak') •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2024-38661 – s390/ap: Fix crash in AP internal function modify_bitmap()
https://notcve.org/view.php?id=CVE-2024-38661
In the Linux kernel, the following vulnerability has been resolved: s390/ap: Fix crash in AP internal function modify_bitmap() A system crash like this Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403 Fault in home space mode while using kernel ASCE. AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d Oops: 0038 ilc:3 [#1] PREEMPT SMP Modules linked in: mlx5_ib ... CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8 Hardware name: IBM 3931 A01 704 (LPAR) Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3 000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0 000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff 000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8 Krnl Code: 0000014b75e7b5fc: a7840047 brc 8,0000014b75e7b68a 0000014b75e7b600: 18b2 lr %r11,%r2 #0000014b75e7b602: a7f4000a brc 15,0000014b75e7b616 >0000014b75e7b606: eb22d00000e6 laog %r2,%r2,0(%r13) 0000014b75e7b60c: a7680001 lhi %r6,1 0000014b75e7b610: 187b lr %r7,%r11 0000014b75e7b612: 84960021 brxh %r9,%r6,0000014b75e7b654 0000014b75e7b616: 18e9 lr %r14,%r9 Call Trace: [<0000014b75e7b606>] ap_parse_bitmap_str+0x10e/0x1f8 ([<0000014b75e7b5dc>] ap_parse_bitmap_str+0xe4/0x1f8) [<0000014b75e7b758>] apmask_store+0x68/0x140 [<0000014b75679196>] kernfs_fop_write_iter+0x14e/0x1e8 [<0000014b75598524>] vfs_write+0x1b4/0x448 [<0000014b7559894c>] ksys_write+0x74/0x100 [<0000014b7618a440>] __do_syscall+0x268/0x328 [<0000014b761a3558>] system_call+0x70/0x98 INFO: lockdep is turned off. Last Breaking-Event-Address: [<0000014b75e7b636>] ap_parse_bitmap_str+0x13e/0x1f8 Kernel panic - not syncing: Fatal exception: panic_on_oops occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value (like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX. The fix is simple: use unsigned long values for the internal variables. The correct checks are already in place in the function but a simple int for the internal variables was used with the possibility to overflow. • https://git.kernel.org/stable/c/2062e3f1f2374102f8014d7ca286b9aa527bd558 https://git.kernel.org/stable/c/7c72af16abf2ec7520407098360bbba312289e05 https://git.kernel.org/stable/c/7360cef95aa1ea2b5efb7b5e2ed32e941664e1f0 https://git.kernel.org/stable/c/67011123453b91ec03671d40712fa213e94a01b9 https://git.kernel.org/stable/c/8c5f5911c1b13170d3404eb992c6a0deaa8d81ad https://git.kernel.org/stable/c/4c0bfb4e867c1ec6616a5049bd3618021e127056 https://git.kernel.org/stable/c/7dabe54a016defe11bb2a278cd9f1ff6db3feba6 https://git.kernel.org/stable/c/d4f9d5a99a3fd1b1c691b7a1a6f8f3f25 •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2024-38385 – genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after()
https://notcve.org/view.php?id=CVE-2024-38385
In the Linux kernel, the following vulnerability has been resolved: genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after() irq_find_at_or_after() dereferences the interrupt descriptor which is returned by mt_find() while neither holding sparse_irq_lock nor RCU read lock, which means the descriptor can be freed between mt_find() and the dereference: CPU0 CPU1 desc = mt_find() delayed_free_desc(desc) irq_desc_get_irq(desc) The use-after-free is reported by KASAN: Call trace: irq_get_next_irq+0x58/0x84 show_stat+0x638/0x824 seq_read_iter+0x158/0x4ec proc_reg_read_iter+0x94/0x12c vfs_read+0x1e0/0x2c8 Freed by task 4471: slab_free_freelist_hook+0x174/0x1e0 __kmem_cache_free+0xa4/0x1dc kfree+0x64/0x128 irq_kobj_release+0x28/0x3c kobject_put+0xcc/0x1e0 delayed_free_desc+0x14/0x2c rcu_do_batch+0x214/0x720 Guard the access with a RCU read lock section. • https://git.kernel.org/stable/c/721255b9826bd11c7a38b585905fc2dd0fb94e52 https://git.kernel.org/stable/c/1c7891812d85500ae2ca4051fa5683fcf29930d8 https://git.kernel.org/stable/c/d084aa022f84319f8079e30882cbcbc026af9f21 https://git.kernel.org/stable/c/b84a8aba806261d2f759ccedf4a2a6a80a5e55ba •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2024-38306 – btrfs: protect folio::private when attaching extent buffer folios
https://notcve.org/view.php?id=CVE-2024-38306
In the Linux kernel, the following vulnerability has been resolved: btrfs: protect folio::private when attaching extent buffer folios [BUG] Since v6.8 there are rare kernel crashes reported by various people, the common factor is bad page status error messages like this: BUG: Bad page state in process kswapd0 pfn:d6e840 page: refcount:0 mapcount:0 mapping:000000007512f4f2 index:0x2796c2c7c pfn:0xd6e840 aops:btree_aops ino:1 flags: 0x17ffffe0000008(uptodate|node=0|zone=2|lastcpupid=0x3fffff) page_type: 0xffffffff() raw: 0017ffffe0000008 dead000000000100 dead000000000122 ffff88826d0be4c0 raw: 00000002796c2c7c 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: non-NULL mapping [CAUSE] Commit 09e6cef19c9f ("btrfs: refactor alloc_extent_buffer() to allocate-then-attach method") changes the sequence when allocating a new extent buffer. Previously we always called grab_extent_buffer() under mapping->i_private_lock, to ensure the safety on modification on folio::private (which is a pointer to extent buffer for regular sectorsize). This can lead to the following race: Thread A is trying to allocate an extent buffer at bytenr X, with 4 4K pages, meanwhile thread B is trying to release the page at X + 4K (the second page of the extent buffer at X). Thread A | Thread B -----------------------------------+------------------------------------- | btree_release_folio() | | This is for the page at X + 4K, | | Not page X. | | alloc_extent_buffer() | |- release_extent_buffer() |- filemap_add_folio() for the | | |- atomic_dec_and_test(eb->refs) | page at bytenr X (the first | | | | page). | | | | Which returned -EEXIST. | | | | | | | |- filemap_lock_folio() | | | | Returned the first page locked. | | | | | | | |- grab_extent_buffer() | | | | |- atomic_inc_not_zero() | | | | | Returned false | | | | |- folio_detach_private() | | |- folio_detach_private() for X | |- folio_test_private() | | |- folio_test_private() | Returned true | | | Returned true |- folio_put() | |- folio_put() Now there are two puts on the same folio at folio X, leading to refcount underflow of the folio X, and eventually causing the BUG_ON() on the page->mapping. The condition is not that easy to hit: - The release must be triggered for the middle page of an eb If the release is on the same first page of an eb, page lock would kick in and prevent the race. - folio_detach_private() has a very small race window It's only between folio_test_private() and folio_clear_private(). That's exactly when mapping->i_private_lock is used to prevent such race, and commit 09e6cef19c9f ("btrfs: refactor alloc_extent_buffer() to allocate-then-attach method") screwed that up. At that time, I thought the page lock would kick in as filemap_release_folio() also requires the page to be locked, but forgot the filemap_release_folio() only locks one page, not all pages of an extent buffer. [FIX] Move all the code requiring i_private_lock into attach_eb_folio_to_filemap(), so that everything is done with proper lock protection. Furthermore to prevent future problems, add an extra lockdep_assert_locked() to ensure we're holding the proper lock. To reproducer that is able to hit the race (takes a few minutes with instrumented code inserting delays to alloc_extent_buffer()): #! • https://git.kernel.org/stable/c/09e6cef19c9fc0e10547135476865b5272aa0406 https://git.kernel.org/stable/c/952f048eb901881a7cc6f7c1368b53cd386ead7b https://git.kernel.org/stable/c/f3a5367c679d31473d3fbb391675055b4792c309 •