Sicherheitslücken in linux-aws · Seite 191

l2tp: prevent possible tunnel refcount underflow

In the Linux kernel, the following vulnerability has been resolved: l2tp: prevent possible tunnel refcount underflow When a session is created, it sets a backpointer to its tunnel. When the session refcount drops to 0, l2tp_session_free drops the tunnel refcount if session->tunnel is non-NULL. However, session->tunnel is set in l2tp_session_create, before the tunnel refcount is incremented by l2tp_session_register, which leaves a small window where session->tunnel is non-NULL when the tunnel refcount hasn't been bumped. Moving the assignment to l2tp_session_register is trivial but l2tp_session_create calls l2tp_session_set_header_len which

wifi: ath9k_htc: Use __skb_set_length() for resetting urb before resubmit

In the Linux kernel, the following vulnerability has been resolved: wifi: ath9k_htc: Use __skb_set_length() for resetting urb before resubmit Syzbot points out that skb_trim() has a sanity check on the existing length of the skb, which can be uninitialised in some error paths. The intent here is clearly just to reset the length to zero before resubmitting, so switch to calling __skb_set_length(skb, 0) directly. In addition, __skb_set_length() already contains a call to skb_reset_tail_pointer(), so remove the redundant call. The syzbot report came from ath9k_hif_usb_reg_in_cb(), but there's a similar usage of skb_trim() in ath9k_hif_usb_rx_

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ACPI: PAD: fix crash in exit_round_robin()

In the Linux kernel, the following vulnerability has been resolved: ACPI: PAD: fix crash in exit_round_robin() The kernel occasionally crashes in cpumask_clear_cpu(), which is called within exit_round_robin(), because when executing clear_bit(nr, addr) with nr set to 0xffffffff, the address calculation may cause misalignment within the memory, leading to access to an invalid memory address. ---------- BUG: unable to handle kernel paging request at ffffffffe0740618 ... CPU: 3 PID: 2919323 Comm: acpi_pad/14 Kdump: loaded Tainted: G OE X --------- - - 4.18.0-425.19.2.el8_7.x86_64 #1 ... RIP: 0010:power_saving_threa

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btrfs: don't readahead the relocation inode on RST

In the Linux kernel, the following vulnerability has been resolved: btrfs: don't readahead the relocation inode on RST On relocation we're doing readahead on the relocation inode, but if the filesystem is backed by a RAID stripe tree we can get ENOENT (e.g. due to preallocated extents not being mapped in the RST) from the lookup. But readahead doesn't handle the error and submits invalid reads to the device, causing an assertion in the scatter-gather list code: BTRFS info (device nvme1n1): balance: start -d -m -s BTRFS info (device nvme1n1): relocating block group 6480920576 flags data|raid0 BTRFS error (device nvme1n1): cannot find

wifi: iwlwifi: mvm: avoid NULL pointer dereference

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mvm: avoid NULL pointer dereference iwl_mvm_tx_skb_sta() and iwl_mvm_tx_mpdu() verify that the mvmvsta pointer is not NULL. It retrieves this pointer using iwl_mvm_sta_from_mac80211, which is dereferencing the ieee80211_sta pointer. If sta is NULL, iwl_mvm_sta_from_mac80211 will dereference a NULL pointer. Fix this by checking the sta pointer before retrieving the mvmsta from it. If sta is not NULL, then mvmsta isn't either.

x86/ioapic: Handle allocation failures gracefully

In the Linux kernel, the following vulnerability has been resolved: x86/ioapic: Handle allocation failures gracefully Breno observed panics when using failslab under certain conditions during runtime: can not alloc irq_pin_list (-1,0,20) Kernel panic - not syncing: IO-APIC: failed to add irq-pin. Can not proceed panic+0x4e9/0x590 mp_irqdomain_alloc+0x9ab/0xa80 irq_domain_alloc_irqs_locked+0x25d/0x8d0 __irq_domain_alloc_irqs+0x80/0x110 mp_map_pin_to_irq+0x645/0x890 acpi_register_gsi_ioapic+0xe6/0x150 hpet_open+0x313/0x480 That's a pointless panic which is a leftover of the historic IO/APIC code which panic'ed du

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fbdev: pxafb: Fix possible use after free in pxafb_task()

In the Linux kernel, the following vulnerability has been resolved: fbdev: pxafb: Fix possible use after free in pxafb_task() In the pxafb_probe function, it calls the pxafb_init_fbinfo function, after which &fbi->task is associated with pxafb_task. Moreover, within this pxafb_init_fbinfo function, the pxafb_blank function within the &pxafb_ops struct is capable of scheduling work. If we remove the module which will call pxafb_remove to make cleanup, it will call unregister_framebuffer function which can call do_unregister_framebuffer to free fbi->fb through put_fb_info(fb_info), while the work mentioned above will be used. The sequence of

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jfs: Fix uaf in dbFreeBits

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix uaf in dbFreeBits [syzbot reported] ================================================================== BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:587 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752 Read of size 8 at addr ffff8880229254b0 by task syz-executor357/5216 CPU: 0 UID: 0 PID: 5216 Comm: syz-executor357 Not tainted 6.11.0-rc3-syzkaller-00156-gd7a5aa4b3c00 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: <TASK> __dump_s

jfs: check if leafidx greater than num leaves per dmap tree

In the Linux kernel, the following vulnerability has been resolved: jfs: check if leafidx greater than num leaves per dmap tree syzbot report a out of bounds in dbSplit, it because dmt_leafidx greater than num leaves per dmap tree, add a checking for dmt_leafidx in dbFindLeaf. Shaggy: Modified sanity check to apply to control pages as well as leaf pages.

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drm/msm/adreno: Assign msm_gpu->pdev earlier to avoid nullptrs

In the Linux kernel, the following vulnerability has been resolved: drm/msm/adreno: Assign msm_gpu->pdev earlier to avoid nullptrs There are some cases, such as the one uncovered by Commit 46d4efcccc68 ("drm/msm/a6xx: Avoid a nullptr dereference when speedbin setting fails") where msm_gpu_cleanup() : platform_set_drvdata(gpu->pdev, NULL); is called on gpu->pdev == NULL, as the GPU device has not been fully initialized yet. Turns out that there's more than just the aforementioned path that causes this to happen (e.g. the case when there's speedbin data in the catalog, but opp-supported-hw is missing in DT). Assigning msm_gpu->pdev earlie

jfs: Fix uninit-value access of new_ea in ea_buffer

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix uninit-value access of new_ea in ea_buffer syzbot reports that lzo1x_1_do_compress is using uninit-value: ===================================================== BUG: KMSAN: uninit-value in lzo1x_1_do_compress+0x19f9/0x2510 lib/lzo/lzo1x_compress.c:178 ... Uninit was stored to memory at: ea_put fs/jfs/xattr.c:639 [inline] ... Local variable ea_buf created at: __jfs_setxattr+0x5d/0x1ae0 fs/jfs/xattr.c:662 __jfs_xattr_set+0xe6/0x1f0 fs/jfs/xattr.c:934 ===================================================== The reason is ea_buf->new_ea is not initialized properl

drm/amd/pm: ensure the fw_info is not null before using it

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: ensure the fw_info is not null before using it This resolves the dereference null return value warning reported by Coverity.

ext4: avoid use-after-free in ext4_ext_show_leaf()

In the Linux kernel, the following vulnerability has been resolved: ext4: avoid use-after-free in ext4_ext_show_leaf() In ext4_find_extent(), path may be freed by error or be reallocated, so using a previously saved *ppath may have been freed and thus may trigger use-after-free, as follows: ext4_split_extent path = *ppath; ext4_split_extent_at(ppath) path = ext4_find_extent(ppath) ext4_split_extent_at(ppath) // ext4_find_extent fails to free path // but zeroout succeeds ext4_ext_show_leaf(inode, path) eh = path[depth].p_hdr // path use-after-free !!! Similar to ext4_split_extent_at(), we use *ppath directly as an

ext4: fix slab-use-after-free in ext4_split_extent_at()

In the Linux kernel, the following vulnerability has been resolved: ext4: fix slab-use-after-free in ext4_split_extent_at() We hit the following use-after-free: ================================================================== BUG: KASAN: slab-use-after-free in ext4_split_extent_at+0xba8/0xcc0 Read of size 2 at addr ffff88810548ed08 by task kworker/u20:0/40 CPU: 0 PID: 40 Comm: kworker/u20:0 Not tainted 6.9.0-dirty #724 Call Trace: <TASK> kasan_report+0x93/0xc0 ext4_split_extent_at+0xba8/0xcc0 ext4_split_extent.isra.0+0x18f/0x500 ext4_split_convert_extents+0x275/0x750 ext4_ext_handle_unwritten_extents+0x73e/0x1580 ext4_ext_map_bloc

ext4: aovid use-after-free in ext4_ext_insert_extent()

In the Linux kernel, the following vulnerability has been resolved: ext4: aovid use-after-free in ext4_ext_insert_extent() As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and cause UAF. Below is a sample trace with dummy values: ext4_ext_insert_extent path = *ppath = 2000 ext4_ext_create_new_leaf(ppath) ext4_find_extent(ppath) path = *ppath = 2000 if (depth > path[0].p_maxdepth) kfree(path = 2000); *ppath = path = NULL; path = kcalloc() = 3000 *ppath = 3000; return path; /* here path

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ext4: fix double brelse() the buffer of the extents path

In the Linux kernel, the following vulnerability has been resolved: ext4: fix double brelse() the buffer of the extents path In ext4_ext_try_to_merge_up(), set path[1].p_bh to NULL after it has been released, otherwise it may be released twice. An example of what triggers this is as follows: split2 map split1 |--------|-------|--------| ext4_ext_map_blocks ext4_ext_handle_unwritten_extents ext4_split_convert_extents // path->p_depth == 0 ext4_split_extent // 1. do split1 ext4_split_extent_at |ext4_ext_insert_extent | ext4_ext_create_new_leaf | ext4_ext_grow_indepth | le16_add

ext4: update orig_path in ext4_find_extent()

In the Linux kernel, the following vulnerability has been resolved: ext4: update orig_path in ext4_find_extent() In ext4_find_extent(), if the path is not big enough, we free it and set *orig_path to NULL. But after reallocating and successfully initializing the path, we don't update *orig_path, in which case the caller gets a valid path but a NULL ppath, and this may cause a NULL pointer dereference or a path memory leak. For example: ext4_split_extent path = *ppath = 2000 ext4_find_extent if (depth > path[0].p_maxdepth) kfree(path = 2000); *orig_path = path = NULL; path = kcalloc() = 3000 ext4_split_extent_at(

ocfs2: fix possible null-ptr-deref in ocfs2_set_buffer_uptodate

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix possible null-ptr-deref in ocfs2_set_buffer_uptodate When doing cleanup, if flags without OCFS2_BH_READAHEAD, it may trigger NULL pointer dereference in the following ocfs2_set_buffer_uptodate() if bh is NULL.

nfsd: map the EBADMSG to nfserr_io to avoid warning

In the Linux kernel, the following vulnerability has been resolved: nfsd: map the EBADMSG to nfserr_io to avoid warning Ext4 will throw -EBADMSG through ext4_readdir when a checksum error occurs, resulting in the following WARNING. Fix it by mapping EBADMSG to nfserr_io. nfsd_buffered_readdir iterate_dir // -EBADMSG -74 ext4_readdir // .iterate_shared ext4_dx_readdir ext4_htree_fill_tree htree_dirblock_to_tree ext4_read_dirblock __ext4_read_dirblock ext4_dirblock_csum_verify warn_no_space_for_csum __warn_no_space_for_csum return ERR_PTR(-EFSBADCRC) // -EBADMSG -74 nfserrno //

btrfs: fix a NULL pointer dereference when failed to start a new trasacntion

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix a NULL pointer dereference when failed to start a new trasacntion [BUG] Syzbot reported a NULL pointer dereference with the following crash: FAULT_INJECTION: forcing a failure. start_transaction+0x830/0x1670 fs/btrfs/transaction.c:676 prepare_to_relocate+0x31f/0x4c0 fs/btrfs/relocation.c:3642 relocate_block_group+0x169/0xd20 fs/btrfs/relocation.c:3678 ... BTRFS info (device loop0): balance: ended with status: -12 Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cc: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null