Incomplete Cleanup

In the Linux kernel, the following vulnerability has been resolved: btrfs: do proper folio cleanup when cow_file_range() failed [BUG] When testing with COW fixup marked as BUG_ON() (this is involved with the new pin_user_pages*() change, which should not result new out-of-band dirty pages), I hit a crash triggered by the BUG_ON() from hitting COW fixup path. This BUG_ON() happens just after a failed btrfs_run_delalloc_range(): BTRFS error (device dm-2): failed to run delalloc range, root 348 ino 405 folio 65536 submit_bitmap 6-15 start 90112 len 106496: -28 ------------[ cut here ]------------ kernel BUG at fs/btrfs/extent_io.c:1444! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 0 UID: 0 PID: 434621 Comm: kworker/u24:8 Tainted: G OE 6.12.0-rc7-custom+ #86 Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] pc : extent_writepage_io+0x2d4/0x308 [btrfs] lr : extent_writepage_io+0x2d4/0x308 [btrfs] Call trace: extent_writepage_io+0x2d4/0x308 [btrfs] extent_writepage+0x218/0x330 [btrfs] extent_write_cache_pages+0x1d4/0x4b0 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190 filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x180/0x3b0 [btrfs] btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8 [btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408 worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: aa1403e1 9402f3ef aa1403e0 9402f36f (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] That failure is mostly from cow_file_range(), where we can hit -ENOSPC. Although the -ENOSPC is already a bug related to our space reservation code, let's just focus on the error handling. For example, we have the following dirty range [0, 64K) of an inode, with 4K sector size and 4K page size: 0 16K 32K 48K 64K |///////////////////////////////////////| |#######################################| Where |///| means page are still dirty, and |###| means the extent io tree has EXTENT_DELALLOC flag. - Enter extent_writepage() for page 0 - Enter btrfs_run_delalloc_range() for range [0, 64K) - Enter cow_file_range() for range [0, 64K) - Function btrfs_reserve_extent() only reserved one 16K extent So we created extent map and ordered extent for range [0, 16K) 0 16K 32K 48K 64K |////////|//////////////////////////////| |<- OE ->|##############################| And range [0, 16K) has its delalloc flag cleared. But since we haven't yet submit any bio, involved 4 pages are still dirty. - Function btrfs_reserve_extent() returns with -ENOSPC Now we have to run error cleanup, which will clear all EXTENT_DELALLOC* flags and clear the dirty flags for the remaining ranges: 0 16K 32K 48K 64K |////////| | | | | Note that range [0, 16K) still has its pages dirty. - Some time later, writeback is triggered again for the range [0, 16K) since the page range still has dirty flags. - btrfs_run_delalloc_range() will do nothing because there is no EXTENT_DELALLOC flag. - extent_writepage_io() finds page 0 has no ordered flag Which falls into the COW fixup path, triggering the BUG_ON(). Unfortunately this error handling bug dates back to the introduction of btrfs. Thankfully with the abuse of COW fixup, at least it won't crash the kernel. [FIX] Instead of immediately unlocking the extent and folios, we keep the extent and folios locked until either erroring out or the whole delalloc range finished. When the whole delalloc range finished without error, we just unlock the whole range with PAGE_SET_ORDERED (and PAGE_UNLOCK for !keep_locked cases) ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: btrfs: do proper folio cleanup when run_delalloc_nocow() failed [BUG] With CONFIG_DEBUG_VM set, test case generic/476 has some chance to crash with the following VM_BUG_ON_FOLIO(): BTRFS error (device dm-3): cow_file_range failed, start 1146880 end 1253375 len 106496 ret -28 BTRFS error (device dm-3): run_delalloc_nocow failed, start 1146880 end 1253375 len 106496 ret -28 page: refcount:4 mapcount:0 mapping:00000000592787cc index:0x12 pfn:0x10664 aops:btrfs_aops [btrfs] ino:101 dentry name(?):"f1774" flags: 0x2fffff80004028(uptodate|lru|private|node=0|zone=2|lastcpupid=0xfffff) page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) ------------[ cut here ]------------ kernel BUG at mm/page-writeback.c:2992! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 2 UID: 0 PID: 3943513 Comm: kworker/u24:15 Tainted: G OE 6.12.0-rc7-custom+ #87 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] pc : folio_clear_dirty_for_io+0x128/0x258 lr : folio_clear_dirty_for_io+0x128/0x258 Call trace: folio_clear_dirty_for_io+0x128/0x258 btrfs_folio_clamp_clear_dirty+0x80/0xd0 [btrfs] __process_folios_contig+0x154/0x268 [btrfs] extent_clear_unlock_delalloc+0x5c/0x80 [btrfs] run_delalloc_nocow+0x5f8/0x760 [btrfs] btrfs_run_delalloc_range+0xa8/0x220 [btrfs] writepage_delalloc+0x230/0x4c8 [btrfs] extent_writepage+0xb8/0x358 [btrfs] extent_write_cache_pages+0x21c/0x4e8 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190 filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x178/0x3a8 [btrfs] btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8 [btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408 worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: 910a8021 a90363f7 a9046bf9 94012379 (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] The first two lines of extra debug messages show the problem is caused by the error handling of run_delalloc_nocow(). E.g. we have the following dirtied range (4K blocksize 4K page size): 0 16K 32K |//////////////////////////////////////| | Pre-allocated | And the range [0, 16K) has a preallocated extent. - Enter run_delalloc_nocow() for range [0, 16K) Which found range [0, 16K) is preallocated, can do the proper NOCOW write. - Enter fallback_to_fow() for range [16K, 32K) Since the range [16K, 32K) is not backed by preallocated extent, we have to go COW. - cow_file_range() failed for range [16K, 32K) So cow_file_range() will do the clean up by clearing folio dirty, unlock the folios. Now the folios in range [16K, 32K) is unlocked. - Enter extent_clear_unlock_delalloc() from run_delalloc_nocow() Which is called with PAGE_START_WRITEBACK to start page writeback. But folios can only be marked writeback when it's properly locked, thus this triggered the VM_BUG_ON_FOLIO(). Furthermore there is another hidden but common bug that run_delalloc_nocow() is not clearing the folio dirty flags in its error handling path. This is the common bug shared between run_delalloc_nocow() and cow_file_range(). [FIX] - Clear folio dirty for range [@start, @cur_offset) Introduce a helper, cleanup_dirty_folios(), which will find and lock the folio in the range, clear the dirty flag and start/end the writeback, with the extra handling for the @locked_folio. - Introduce a helper to clear folio dirty, start and end writeback - Introduce a helper to record the last failed COW range end This is to trace which range we should skip, to avoid double unlocking. - Skip the failed COW range for the e ---truncated---Show less

In NetX HTTP server functionality of Eclipse ThreadX NetX Duo before version 6.4.2, an attacker can cause a denial of service by specially crafted packets. The core issue is missing closing of a file in case of an error condition, resulting in the 404 error for each further file request. Users can work-around the issue by disabling the PUT request support.Show less

Vulnerability in the PMB platform that allows an attacker to persist temporary files on the server, affecting versions 4.0.10 and above. This vulnerability exists in the file upload functionality on the ‘/pmb/authorities/import/iimport_authorities’ endpoint. When a file is uploaded via this resource, the server will create a temporary file that will be deleted after the client sends a POST request to ‘/pmb/authorities/import/iimport_authorities’. This workflow is automated by the web client, however an attacker can trap and launch the second POST request to prevent the temporary file from being deleted.Show less

SiYuan is self-hosted, open source personal knowledge management software. SiYuan Note version 3.1.18 has an arbitrary file deletion vulnerability. The vulnerability exists in the `POST /api/history/getDocHistoryContent` endpoint. An attacker can craft a payload to exploit this vulnerability, resulting in the deletion of arbitrary files on the server. Commit d9887aeec1b27073bec66299a9a4181dc42969f3 fixes this vulnerability and is expected to be available in version 3.1.19.Show less

In the Linux kernel, the following vulnerability has been resolved: ixgbevf: Fix resource leak in ixgbevf_init_module() ixgbevf_init_module() won't destroy the workqueue created by create_singlethread_workqueue() when pci_register_driver() failed. Add destroy_workqueue() in fail path to prevent the resource leak. Similar to the handling of u132_hcd_init in commit f276e002793c ("usb: u132-hcd: fix resource leak")Show less

In the Linux kernel, the following vulnerability has been resolved: afs: Fix server->active leak in afs_put_server The atomic_read was accidentally replaced with atomic_inc_return, which prevents the server from getting cleaned up and causes rmmod to hang with a warning: Can't purge s=00000001Show less

In the Linux kernel, the following vulnerability has been resolved: tpm: Clean up TPM space after command failure tpm_dev_transmit prepares the TPM space before attempting command transmission. However if the command fails no rollback of this preparation is done. This can result in transient handles being leaked if the device is subsequently closed with no further commands performed. Fix this by flushing the space in the event of command transmission failure.Show less

In the Linux kernel, the following vulnerability has been resolved: drivers/perf: Fix ali_drw_pmu driver interrupt status clearing The alibaba_uncore_pmu driver forgot to clear all interrupt status in the interrupt processing function. After the PMU counter overflow interrupt occurred, an interrupt storm occurred, causing the system to hang. Therefore, clear the correct interrupt status in the interrupt handling function to fix it.Show less

In the Linux kernel, the following vulnerability has been resolved: bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error For all non-tracing helpers which formerly had ARG_PTR_TO_{LONG,INT} as input arguments, zero the value for the case of an error as otherwise it could leak memory. For tracing, it is not needed given CAP_PERFMON can already read all kernel memory anyway hence bpf_get_func_arg() and bpf_get_func_ret() is skipped in here. Also, the MTU helpers mtu_len pointer value is being written but also read. Technically, the MEM_UNINIT should not be there in order to always force init. Removing MEM_UNINIT needs more verifier rework though: MEM_UNINIT right now implies two things actually: i) write into memory, ii) memory does not have to be initialized. If we lift MEM_UNINIT, it then becomes: i) read into memory, ii) memory must be initialized. This means that for bpf_*_check_mtu() we're readding the issue we're trying to fix, that is, it would then be able to write back into things like .rodata BPF maps. Follow-up work will rework the MEM_UNINIT semantics such that the intent can be better expressed. For now just clear the *mtu_len on error path which can be lifted later again.Show less

In the Linux kernel, the following vulnerability has been resolved: IB/core: Fix ib_cache_setup_one error flow cleanup When ib_cache_update return an error, we exit ib_cache_setup_one instantly with no proper cleanup, even though before this we had already successfully done gid_table_setup_one, that results in the kernel WARN below. Do proper cleanup using gid_table_cleanup_one before returning the err in order to fix the issue. WARNING: CPU: 4 PID: 922 at drivers/infiniband/core/cache.c:806 gid_table_release_one+0x181/0x1a0 Modules linked in: CPU: 4 UID: 0 PID: 922 Comm: c_repro Not tainted 6.11.0-rc1+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:gid_table_release_one+0x181/0x1a0 Code: 44 8b 38 75 0c e8 2f cb 34 ff 4d 8b b5 28 05 00 00 e8 23 cb 34 ff 44 89 f9 89 da 4c 89 f6 48 c7 c7 d0 58 14 83 e8 4f de 21 ff <0f> 0b 4c 8b 75 30 e9 54 ff ff ff 48 8 3 c4 10 5b 5d 41 5c 41 5d 41 RSP: 0018:ffffc90002b835b0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811c8527 RDX: 0000000000000000 RSI: ffffffff811c8534 RDI: 0000000000000001 RBP: ffff8881011b3d00 R08: ffff88810b3abe00 R09: 205d303839303631 R10: 666572207972746e R11: 72746e6520444947 R12: 0000000000000001 R13: ffff888106390000 R14: ffff8881011f2110 R15: 0000000000000001 FS: 00007fecc3b70800(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000340 CR3: 000000010435a001 CR4: 00000000003706b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? show_regs+0x94/0xa0 ? __warn+0x9e/0x1c0 ? gid_table_release_one+0x181/0x1a0 ? report_bug+0x1f9/0x340 ? gid_table_release_one+0x181/0x1a0 ? handle_bug+0xa2/0x110 ? exc_invalid_op+0x31/0xa0 ? asm_exc_invalid_op+0x16/0x20 ? __warn_printk+0xc7/0x180 ? __warn_printk+0xd4/0x180 ? gid_table_release_one+0x181/0x1a0 ib_device_release+0x71/0xe0 ? __pfx_ib_device_release+0x10/0x10 device_release+0x44/0xd0 kobject_put+0x135/0x3d0 put_device+0x20/0x30 rxe_net_add+0x7d/0xa0 rxe_newlink+0xd7/0x190 nldev_newlink+0x1b0/0x2a0 ? __pfx_nldev_newlink+0x10/0x10 rdma_nl_rcv_msg+0x1ad/0x2e0 rdma_nl_rcv_skb.constprop.0+0x176/0x210 netlink_unicast+0x2de/0x400 netlink_sendmsg+0x306/0x660 __sock_sendmsg+0x110/0x120 ____sys_sendmsg+0x30e/0x390 ___sys_sendmsg+0x9b/0xf0 ? kstrtouint+0x6e/0xa0 ? kstrtouint_from_user+0x7c/0xb0 ? get_pid_task+0xb0/0xd0 ? proc_fail_nth_write+0x5b/0x140 ? __fget_light+0x9a/0x200 ? preempt_count_add+0x47/0xa0 __sys_sendmsg+0x61/0xd0 do_syscall_64+0x50/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7eShow less

In the Linux kernel, the following vulnerability has been resolved: mm: avoid leaving partial pfn mappings around in error case As Jann points out, PFN mappings are special, because unlike normal memory mappings, there is no lifetime information associated with the mapping - it is just a raw mapping of PFNs with no reference counting of a 'struct page'. That's all very much intentional, but it does mean that it's easy to mess up the cleanup in case of errors. Yes, a failed mmap() will always eventually clean up any partial mappings, but without any explicit lifetime in the page table mapping itself, it's very easy to do the error handling in the wrong order. In particular, it's easy to mistakenly free the physical backing store before the page tables are actually cleaned up and (temporarily) have stale dangling PTE entries. To make this situation less error-prone, just make sure that any partial pfn mapping is torn down early, before any other error handling.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: xhci: Check for xhci->interrupters being allocated in xhci_mem_clearup() If xhci_mem_init() fails, it calls into xhci_mem_cleanup() to mop up the damage. If it fails early enough, before xhci->interrupters is allocated but after xhci->max_interrupters has been set, which happens in most (all?) cases, things get uglier, as xhci_mem_cleanup() unconditionally derefences xhci->interrupters. With prejudice. Gate the interrupt freeing loop with a check on xhci->interrupters being non-NULL. Found while debugging a DMA allocation issue that led the XHCI driver on this exact path.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/msm/dpu: cleanup FB if dpu_format_populate_layout fails If the dpu_format_populate_layout() fails, then FB is prepared, but not cleaned up. This ends up leaking the pin_count on the GEM object and causes a splat during DRM file closure: msm_obj->pin_count WARNING: CPU: 2 PID: 569 at drivers/gpu/drm/msm/msm_gem.c:121 update_lru_locked+0xc4/0xcc [...] Call trace: update_lru_locked+0xc4/0xcc put_pages+0xac/0x100 msm_gem_free_object+0x138/0x180 drm_gem_object_free+0x1c/0x30 drm_gem_object_handle_put_unlocked+0x108/0x10c drm_gem_object_release_handle+0x58/0x70 idr_for_each+0x68/0xec drm_gem_release+0x28/0x40 drm_file_free+0x174/0x234 drm_release+0xb0/0x160 __fput+0xc0/0x2c8 __fput_sync+0x50/0x5c __arm64_sys_close+0x38/0x7c invoke_syscall+0x48/0x118 el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x4c/0x120 el0t_64_sync_handler+0x100/0x12c el0t_64_sync+0x190/0x194 irq event stamp: 129818 hardirqs last enabled at (129817): [<ffffa5f6d953fcc0>] console_unlock+0x118/0x124 hardirqs last disabled at (129818): [<ffffa5f6da7dcf04>] el1_dbg+0x24/0x8c softirqs last enabled at (129808): [<ffffa5f6d94afc18>] handle_softirqs+0x4c8/0x4e8 softirqs last disabled at (129785): [<ffffa5f6d94105e4>] __do_softirq+0x14/0x20 Patchwork: https://patchwork.freedesktop.org/patch/600714/Show less

In the Linux kernel, the following vulnerability has been resolved: drm/i915/gt: Cleanup partial engine discovery failures If we abort driver initialisation in the middle of gt/engine discovery, some engines will be fully setup and some not. Those incompletely setup engines only have 'engine->release == NULL' and so will leak any of the common objects allocated. v2: - Drop the destroy_pinned_context() helper for now. It's not really worth it with just a single callsite at the moment. (Janusz)Show less