| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrum_acl_tcam: Fix possible use-after-free during activity update
The rule activity update delayed work periodically traverses the list of
configured rules and queries their activity from the device.
As part of this task it accesses the entry pointed by 'ventry->entry',
but this entry can be changed concurrently by the rehash delayed work,
leading to a use-after-free [1].
Fix by closing the race and perform the activity query under the
'vregion->lock' mutex.
[1]
BUG: KASAN: slab-use-after-free in mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140
Read of size 8 at addr ffff8881054ed808 by task kworker/0:18/181
CPU: 0 PID: 181 Comm: kworker/0:18 Not tainted 6.9.0-rc2-custom-00781-gd5ab772d32f7 #2
Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019
Workqueue: mlxsw_core mlxsw_sp_acl_rule_activity_update_work
Call Trace:
<TASK>
dump_stack_lvl+0xc6/0x120
print_report+0xce/0x670
kasan_report+0xd7/0x110
mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140
mlxsw_sp_acl_rule_activity_update_work+0x219/0x400
process_one_work+0x8eb/0x19b0
worker_thread+0x6c9/0xf70
kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 1039:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x8f/0xa0
__kmalloc+0x19c/0x360
mlxsw_sp_acl_tcam_entry_create+0x7b/0x1f0
mlxsw_sp_acl_tcam_vchunk_migrate_all+0x30d/0xb50
mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300
process_one_work+0x8eb/0x19b0
worker_thread+0x6c9/0xf70
kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80
ret_from_fork_asm+0x1a/0x30
Freed by task 1039:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
poison_slab_object+0x102/0x170
__kasan_slab_free+0x14/0x30
kfree+0xc1/0x290
mlxsw_sp_acl_tcam_vchunk_migrate_all+0x3d7/0xb50
mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300
process_one_work+0x8eb/0x19b0
worker_thread+0x6c9/0xf70
kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80
ret_from_fork_asm+0x1a/0x30 |
| In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrum_acl_tcam: Fix memory leak during rehash
The rehash delayed work migrates filters from one region to another.
This is done by iterating over all chunks (all the filters with the same
priority) in the region and in each chunk iterating over all the
filters.
If the migration fails, the code tries to migrate the filters back to
the old region. However, the rollback itself can also fail in which case
another migration will be erroneously performed. Besides the fact that
this ping pong is not a very good idea, it also creates a problem.
Each virtual chunk references two chunks: The currently used one
('vchunk->chunk') and a backup ('vchunk->chunk2'). During migration the
first holds the chunk we want to migrate filters to and the second holds
the chunk we are migrating filters from.
The code currently assumes - but does not verify - that the backup chunk
does not exist (NULL) if the currently used chunk does not reference the
target region. This assumption breaks when we are trying to rollback a
rollback, resulting in the backup chunk being overwritten and leaked
[1].
Fix by not rolling back a failed rollback and add a warning to avoid
future cases.
[1]
WARNING: CPU: 5 PID: 1063 at lib/parman.c:291 parman_destroy+0x17/0x20
Modules linked in:
CPU: 5 PID: 1063 Comm: kworker/5:11 Tainted: G W 6.9.0-rc2-custom-00784-gc6a05c468a0b #14
Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019
Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work
RIP: 0010:parman_destroy+0x17/0x20
[...]
Call Trace:
<TASK>
mlxsw_sp_acl_atcam_region_fini+0x19/0x60
mlxsw_sp_acl_tcam_region_destroy+0x49/0xf0
mlxsw_sp_acl_tcam_vregion_rehash_work+0x1f1/0x470
process_one_work+0x151/0x370
worker_thread+0x2cb/0x3e0
kthread+0xd0/0x100
ret_from_fork+0x34/0x50
ret_from_fork_asm+0x1a/0x30
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrum_acl_tcam: Fix memory leak when canceling rehash work
The rehash delayed work is rescheduled with a delay if the number of
credits at end of the work is not negative as supposedly it means that
the migration ended. Otherwise, it is rescheduled immediately.
After "mlxsw: spectrum_acl_tcam: Fix possible use-after-free during
rehash" the above is no longer accurate as a non-negative number of
credits is no longer indicative of the migration being done. It can also
happen if the work encountered an error in which case the migration will
resume the next time the work is scheduled.
The significance of the above is that it is possible for the work to be
pending and associated with hints that were allocated when the migration
started. This leads to the hints being leaked [1] when the work is
canceled while pending as part of ACL region dismantle.
Fix by freeing the hints if hints are associated with a work that was
canceled while pending.
Blame the original commit since the reliance on not having a pending
work associated with hints is fragile.
[1]
unreferenced object 0xffff88810e7c3000 (size 256):
comm "kworker/0:16", pid 176, jiffies 4295460353
hex dump (first 32 bytes):
00 30 95 11 81 88 ff ff 61 00 00 00 00 00 00 80 .0......a.......
00 00 61 00 40 00 00 00 00 00 00 00 04 00 00 00 ..a.@...........
backtrace (crc 2544ddb9):
[<00000000cf8cfab3>] kmalloc_trace+0x23f/0x2a0
[<000000004d9a1ad9>] objagg_hints_get+0x42/0x390
[<000000000b143cf3>] mlxsw_sp_acl_erp_rehash_hints_get+0xca/0x400
[<0000000059bdb60a>] mlxsw_sp_acl_tcam_vregion_rehash_work+0x868/0x1160
[<00000000e81fd734>] process_one_work+0x59c/0xf20
[<00000000ceee9e81>] worker_thread+0x799/0x12c0
[<00000000bda6fe39>] kthread+0x246/0x300
[<0000000070056d23>] ret_from_fork+0x34/0x70
[<00000000dea2b93e>] ret_from_fork_asm+0x1a/0x30 |
| In the Linux kernel, the following vulnerability has been resolved:
irqchip/gic-v3-its: Prevent double free on error
The error handling path in its_vpe_irq_domain_alloc() causes a double free
when its_vpe_init() fails after successfully allocating at least one
interrupt. This happens because its_vpe_irq_domain_free() frees the
interrupts along with the area bitmap and the vprop_page and
its_vpe_irq_domain_alloc() subsequently frees the area bitmap and the
vprop_page again.
Fix this by unconditionally invoking its_vpe_irq_domain_free() which
handles all cases correctly and by removing the bitmap/vprop_page freeing
from its_vpe_irq_domain_alloc().
[ tglx: Massaged change log ] |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix deadlock while reading mqd from debugfs
An errant disk backup on my desktop got into debugfs and triggered the
following deadlock scenario in the amdgpu debugfs files. The machine
also hard-resets immediately after those lines are printed (although I
wasn't able to reproduce that part when reading by hand):
[ 1318.016074][ T1082] ======================================================
[ 1318.016607][ T1082] WARNING: possible circular locking dependency detected
[ 1318.017107][ T1082] 6.8.0-rc7-00015-ge0c8221b72c0 #17 Not tainted
[ 1318.017598][ T1082] ------------------------------------------------------
[ 1318.018096][ T1082] tar/1082 is trying to acquire lock:
[ 1318.018585][ T1082] ffff98c44175d6a0 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x40/0x80
[ 1318.019084][ T1082]
[ 1318.019084][ T1082] but task is already holding lock:
[ 1318.020052][ T1082] ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]
[ 1318.020607][ T1082]
[ 1318.020607][ T1082] which lock already depends on the new lock.
[ 1318.020607][ T1082]
[ 1318.022081][ T1082]
[ 1318.022081][ T1082] the existing dependency chain (in reverse order) is:
[ 1318.023083][ T1082]
[ 1318.023083][ T1082] -> #2 (reservation_ww_class_mutex){+.+.}-{3:3}:
[ 1318.024114][ T1082] __ww_mutex_lock.constprop.0+0xe0/0x12f0
[ 1318.024639][ T1082] ww_mutex_lock+0x32/0x90
[ 1318.025161][ T1082] dma_resv_lockdep+0x18a/0x330
[ 1318.025683][ T1082] do_one_initcall+0x6a/0x350
[ 1318.026210][ T1082] kernel_init_freeable+0x1a3/0x310
[ 1318.026728][ T1082] kernel_init+0x15/0x1a0
[ 1318.027242][ T1082] ret_from_fork+0x2c/0x40
[ 1318.027759][ T1082] ret_from_fork_asm+0x11/0x20
[ 1318.028281][ T1082]
[ 1318.028281][ T1082] -> #1 (reservation_ww_class_acquire){+.+.}-{0:0}:
[ 1318.029297][ T1082] dma_resv_lockdep+0x16c/0x330
[ 1318.029790][ T1082] do_one_initcall+0x6a/0x350
[ 1318.030263][ T1082] kernel_init_freeable+0x1a3/0x310
[ 1318.030722][ T1082] kernel_init+0x15/0x1a0
[ 1318.031168][ T1082] ret_from_fork+0x2c/0x40
[ 1318.031598][ T1082] ret_from_fork_asm+0x11/0x20
[ 1318.032011][ T1082]
[ 1318.032011][ T1082] -> #0 (&mm->mmap_lock){++++}-{3:3}:
[ 1318.032778][ T1082] __lock_acquire+0x14bf/0x2680
[ 1318.033141][ T1082] lock_acquire+0xcd/0x2c0
[ 1318.033487][ T1082] __might_fault+0x58/0x80
[ 1318.033814][ T1082] amdgpu_debugfs_mqd_read+0x103/0x250 [amdgpu]
[ 1318.034181][ T1082] full_proxy_read+0x55/0x80
[ 1318.034487][ T1082] vfs_read+0xa7/0x360
[ 1318.034788][ T1082] ksys_read+0x70/0xf0
[ 1318.035085][ T1082] do_syscall_64+0x94/0x180
[ 1318.035375][ T1082] entry_SYSCALL_64_after_hwframe+0x46/0x4e
[ 1318.035664][ T1082]
[ 1318.035664][ T1082] other info that might help us debug this:
[ 1318.035664][ T1082]
[ 1318.036487][ T1082] Chain exists of:
[ 1318.036487][ T1082] &mm->mmap_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex
[ 1318.036487][ T1082]
[ 1318.037310][ T1082] Possible unsafe locking scenario:
[ 1318.037310][ T1082]
[ 1318.037838][ T1082] CPU0 CPU1
[ 1318.038101][ T1082] ---- ----
[ 1318.038350][ T1082] lock(reservation_ww_class_mutex);
[ 1318.038590][ T1082] lock(reservation_ww_class_acquire);
[ 1318.038839][ T1082] lock(reservation_ww_class_mutex);
[ 1318.039083][ T1082] rlock(&mm->mmap_lock);
[ 1318.039328][ T1082]
[ 1318.039328][ T1082] *** DEADLOCK ***
[ 1318.039328][ T1082]
[ 1318.040029][ T1082] 1 lock held by tar/1082:
[ 1318.040259][ T1082] #0: ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]
[ 1318.040560][ T1082]
[ 1318.040560][ T1082] stack backtrace:
[
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix NULL domain on device release
In the kdump kernel, the IOMMU operates in deferred_attach mode. In this
mode, info->domain may not yet be assigned by the time the release_device
function is called. It leads to the following crash in the crash kernel:
BUG: kernel NULL pointer dereference, address: 000000000000003c
...
RIP: 0010:do_raw_spin_lock+0xa/0xa0
...
_raw_spin_lock_irqsave+0x1b/0x30
intel_iommu_release_device+0x96/0x170
iommu_deinit_device+0x39/0xf0
__iommu_group_remove_device+0xa0/0xd0
iommu_bus_notifier+0x55/0xb0
notifier_call_chain+0x5a/0xd0
blocking_notifier_call_chain+0x41/0x60
bus_notify+0x34/0x50
device_del+0x269/0x3d0
pci_remove_bus_device+0x77/0x100
p2sb_bar+0xae/0x1d0
...
i801_probe+0x423/0x740
Use the release_domain mechanism to fix it. The scalable mode context
entry which is not part of release domain should be cleared in
release_device(). |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7925e: fix use-after-free in free_irq()
From commit a304e1b82808 ("[PATCH] Debug shared irqs"), there is a test
to make sure the shared irq handler should be able to handle the unexpected
event after deregistration. For this case, let's apply MT76_REMOVED flag to
indicate the device was removed and do not run into the resource access
anymore. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: brcm80211: handle pmk_op allocation failure
The kzalloc() in brcmf_pmksa_v3_op() will return null if the
physical memory has run out. As a result, if we dereference
the null value, the null pointer dereference bug will happen.
Return -ENOMEM from brcmf_pmksa_v3_op() if kzalloc() fails
for pmk_op. |
| In the Linux kernel, the following vulnerability has been resolved:
nfp: flower: handle acti_netdevs allocation failure
The kmalloc_array() in nfp_fl_lag_do_work() will return null, if
the physical memory has run out. As a result, if we dereference
the acti_netdevs, the null pointer dereference bugs will happen.
This patch adds a check to judge whether allocation failure occurs.
If it happens, the delayed work will be rescheduled and try again. |
| In the Linux kernel, the following vulnerability has been resolved:
media: edia: dvbdev: fix a use-after-free
In dvb_register_device, *pdvbdev is set equal to dvbdev, which is freed
in several error-handling paths. However, *pdvbdev is not set to NULL
after dvbdev's deallocation, causing use-after-frees in many places,
for example, in the following call chain:
budget_register
|-> dvb_dmxdev_init
|-> dvb_register_device
|-> dvb_dmxdev_release
|-> dvb_unregister_device
|-> dvb_remove_device
|-> dvb_device_put
|-> kref_put
When calling dvb_unregister_device, dmxdev->dvbdev (i.e. *pdvbdev in
dvb_register_device) could point to memory that had been freed in
dvb_register_device. Thereafter, this pointer is transferred to
kref_put and triggering a use-after-free. |
| In the Linux kernel, the following vulnerability has been resolved:
powercap: intel_rapl: Fix a NULL pointer dereference
A NULL pointer dereference is triggered when probing the MMIO RAPL
driver on platforms with CPU ID not listed in intel_rapl_common CPU
model list.
This is because the intel_rapl_common module still probes on such
platforms even if 'defaults_msr' is not set after commit 1488ac990ac8
("powercap: intel_rapl: Allow probing without CPUID match"). Thus the
MMIO RAPL rp->priv->defaults is NULL when registering to RAPL framework.
Fix the problem by adding sanity check to ensure rp->priv->rapl_defaults
is always valid. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: xhci: Add error handling in xhci_map_urb_for_dma
Currently xhci_map_urb_for_dma() creates a temporary buffer and copies
the SG list to the new linear buffer. But if the kzalloc_node() fails,
then the following sg_pcopy_to_buffer() can lead to crash since it
tries to memcpy to NULL pointer.
So return -ENOMEM if kzalloc returns null pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/vmwgfx: Create debugfs ttm_resource_manager entry only if needed
The driver creates /sys/kernel/debug/dri/0/mob_ttm even when the
corresponding ttm_resource_manager is not allocated.
This leads to a crash when trying to read from this file.
Add a check to create mob_ttm, system_mob_ttm, and gmr_ttm debug file
only when the corresponding ttm_resource_manager is allocated.
crash> bt
PID: 3133409 TASK: ffff8fe4834a5000 CPU: 3 COMMAND: "grep"
#0 [ffffb954506b3b20] machine_kexec at ffffffffb2a6bec3
#1 [ffffb954506b3b78] __crash_kexec at ffffffffb2bb598a
#2 [ffffb954506b3c38] crash_kexec at ffffffffb2bb68c1
#3 [ffffb954506b3c50] oops_end at ffffffffb2a2a9b1
#4 [ffffb954506b3c70] no_context at ffffffffb2a7e913
#5 [ffffb954506b3cc8] __bad_area_nosemaphore at ffffffffb2a7ec8c
#6 [ffffb954506b3d10] do_page_fault at ffffffffb2a7f887
#7 [ffffb954506b3d40] page_fault at ffffffffb360116e
[exception RIP: ttm_resource_manager_debug+0x11]
RIP: ffffffffc04afd11 RSP: ffffb954506b3df0 RFLAGS: 00010246
RAX: ffff8fe41a6d1200 RBX: 0000000000000000 RCX: 0000000000000940
RDX: 0000000000000000 RSI: ffffffffc04b4338 RDI: 0000000000000000
RBP: ffffb954506b3e08 R8: ffff8fee3ffad000 R9: 0000000000000000
R10: ffff8fe41a76a000 R11: 0000000000000001 R12: 00000000ffffffff
R13: 0000000000000001 R14: ffff8fe5bb6f3900 R15: ffff8fe41a6d1200
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#8 [ffffb954506b3e00] ttm_resource_manager_show at ffffffffc04afde7 [ttm]
#9 [ffffb954506b3e30] seq_read at ffffffffb2d8f9f3
RIP: 00007f4c4eda8985 RSP: 00007ffdbba9e9f8 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 000000000037e000 RCX: 00007f4c4eda8985
RDX: 000000000037e000 RSI: 00007f4c41573000 RDI: 0000000000000003
RBP: 000000000037e000 R8: 0000000000000000 R9: 000000000037fe30
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4c41573000
R13: 0000000000000003 R14: 00007f4c41572010 R15: 0000000000000003
ORIG_RAX: 0000000000000000 CS: 0033 SS: 002b |
| In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix deadlock in port "disable" sysfs attribute
The show and store callback routines for the "disable" sysfs attribute
file in port.c acquire the device lock for the port's parent hub
device. This can cause problems if another process has locked the hub
to remove it or change its configuration:
Removing the hub or changing its configuration requires the
hub interface to be removed, which requires the port device
to be removed, and device_del() waits until all outstanding
sysfs attribute callbacks for the ports have returned. The
lock can't be released until then.
But the disable_show() or disable_store() routine can't return
until after it has acquired the lock.
The resulting deadlock can be avoided by calling
sysfs_break_active_protection(). This will cause the sysfs core not
to wait for the attribute's callback routine to return, allowing the
removal to proceed. The disadvantage is that after making this call,
there is no guarantee that the hub structure won't be deallocated at
any moment. To prevent this, we have to acquire a reference to it
first by calling hub_get(). |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: SOF: Add some bounds checking to firmware data
Smatch complains about "head->full_size - head->header_size" can
underflow. To some extent, we're always going to have to trust the
firmware a bit. However, it's easy enough to add a check for negatives,
and let's add a upper bounds check as well. |
| In the Linux kernel, the following vulnerability has been resolved:
md: fix kmemleak of rdev->serial
If kobject_add() is fail in bind_rdev_to_array(), 'rdev->serial' will be
alloc not be freed, and kmemleak occurs.
unreferenced object 0xffff88815a350000 (size 49152):
comm "mdadm", pid 789, jiffies 4294716910
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc f773277a):
[<0000000058b0a453>] kmemleak_alloc+0x61/0xe0
[<00000000366adf14>] __kmalloc_large_node+0x15e/0x270
[<000000002e82961b>] __kmalloc_node.cold+0x11/0x7f
[<00000000f206d60a>] kvmalloc_node+0x74/0x150
[<0000000034bf3363>] rdev_init_serial+0x67/0x170
[<0000000010e08fe9>] mddev_create_serial_pool+0x62/0x220
[<00000000c3837bf0>] bind_rdev_to_array+0x2af/0x630
[<0000000073c28560>] md_add_new_disk+0x400/0x9f0
[<00000000770e30ff>] md_ioctl+0x15bf/0x1c10
[<000000006cfab718>] blkdev_ioctl+0x191/0x3f0
[<0000000085086a11>] vfs_ioctl+0x22/0x60
[<0000000018b656fe>] __x64_sys_ioctl+0xba/0xe0
[<00000000e54e675e>] do_syscall_64+0x71/0x150
[<000000008b0ad622>] entry_SYSCALL_64_after_hwframe+0x6c/0x74 |
| In the Linux kernel, the following vulnerability has been resolved:
block: fix deadlock between bd_link_disk_holder and partition scan
'open_mutex' of gendisk is used to protect open/close block devices. But
in bd_link_disk_holder(), it is used to protect the creation of symlink
between holding disk and slave bdev, which introduces some issues.
When bd_link_disk_holder() is called, the driver is usually in the process
of initialization/modification and may suspend submitting io. At this
time, any io hold 'open_mutex', such as scanning partitions, can cause
deadlocks. For example, in raid:
T1 T2
bdev_open_by_dev
lock open_mutex [1]
...
efi_partition
...
md_submit_bio
md_ioctl mddev_syspend
-> suspend all io
md_add_new_disk
bind_rdev_to_array
bd_link_disk_holder
try lock open_mutex [2]
md_handle_request
-> wait mddev_resume
T1 scan partition, T2 add a new device to raid. T1 waits for T2 to resume
mddev, but T2 waits for open_mutex held by T1. Deadlock occurs.
Fix it by introducing a local mutex 'blk_holder_mutex' to replace
'open_mutex'. |
| In the Linux kernel, the following vulnerability has been resolved:
cachefiles: fix memory leak in cachefiles_add_cache()
The following memory leak was reported after unbinding /dev/cachefiles:
==================================================================
unreferenced object 0xffff9b674176e3c0 (size 192):
comm "cachefilesd2", pid 680, jiffies 4294881224
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc ea38a44b):
[<ffffffff8eb8a1a5>] kmem_cache_alloc+0x2d5/0x370
[<ffffffff8e917f86>] prepare_creds+0x26/0x2e0
[<ffffffffc002eeef>] cachefiles_determine_cache_security+0x1f/0x120
[<ffffffffc00243ec>] cachefiles_add_cache+0x13c/0x3a0
[<ffffffffc0025216>] cachefiles_daemon_write+0x146/0x1c0
[<ffffffff8ebc4a3b>] vfs_write+0xcb/0x520
[<ffffffff8ebc5069>] ksys_write+0x69/0xf0
[<ffffffff8f6d4662>] do_syscall_64+0x72/0x140
[<ffffffff8f8000aa>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
==================================================================
Put the reference count of cache_cred in cachefiles_daemon_unbind() to
fix the problem. And also put cache_cred in cachefiles_add_cache() error
branch to avoid memory leaks. |
| In the Linux kernel, the following vulnerability has been resolved:
net: bridge: switchdev: Skip MDB replays of deferred events on offload
Before this change, generation of the list of MDB events to replay
would race against the creation of new group memberships, either from
the IGMP/MLD snooping logic or from user configuration.
While new memberships are immediately visible to walkers of
br->mdb_list, the notification of their existence to switchdev event
subscribers is deferred until a later point in time. So if a replay
list was generated during a time that overlapped with such a window,
it would also contain a replay of the not-yet-delivered event.
The driver would thus receive two copies of what the bridge internally
considered to be one single event. On destruction of the bridge, only
a single membership deletion event was therefore sent. As a
consequence of this, drivers which reference count memberships (at
least DSA), would be left with orphan groups in their hardware
database when the bridge was destroyed.
This is only an issue when replaying additions. While deletion events
may still be pending on the deferred queue, they will already have
been removed from br->mdb_list, so no duplicates can be generated in
that scenario.
To a user this meant that old group memberships, from a bridge in
which a port was previously attached, could be reanimated (in
hardware) when the port joined a new bridge, without the new bridge's
knowledge.
For example, on an mv88e6xxx system, create a snooping bridge and
immediately add a port to it:
root@infix-06-0b-00:~$ ip link add dev br0 up type bridge mcast_snooping 1 && \
> ip link set dev x3 up master br0
And then destroy the bridge:
root@infix-06-0b-00:~$ ip link del dev br0
root@infix-06-0b-00:~$ mvls atu
ADDRESS FID STATE Q F 0 1 2 3 4 5 6 7 8 9 a
DEV:0 Marvell 88E6393X
33:33:00:00:00:6a 1 static - - 0 . . . . . . . . . .
33:33:ff:87:e4:3f 1 static - - 0 . . . . . . . . . .
ff:ff:ff:ff:ff:ff 1 static - - 0 1 2 3 4 5 6 7 8 9 a
root@infix-06-0b-00:~$
The two IPv6 groups remain in the hardware database because the
port (x3) is notified of the host's membership twice: once via the
original event and once via a replay. Since only a single delete
notification is sent, the count remains at 1 when the bridge is
destroyed.
Then add the same port (or another port belonging to the same hardware
domain) to a new bridge, this time with snooping disabled:
root@infix-06-0b-00:~$ ip link add dev br1 up type bridge mcast_snooping 0 && \
> ip link set dev x3 up master br1
All multicast, including the two IPv6 groups from br0, should now be
flooded, according to the policy of br1. But instead the old
memberships are still active in the hardware database, causing the
switch to only forward traffic to those groups towards the CPU (port
0).
Eliminate the race in two steps:
1. Grab the write-side lock of the MDB while generating the replay
list.
This prevents new memberships from showing up while we are generating
the replay list. But it leaves the scenario in which a deferred event
was already generated, but not delivered, before we grabbed the
lock. Therefore:
2. Make sure that no deferred version of a replay event is already
enqueued to the switchdev deferred queue, before adding it to the
replay list, when replaying additions. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: set dormant flag on hook register failure
We need to set the dormant flag again if we fail to register
the hooks.
During memory pressure hook registration can fail and we end up
with a table marked as active but no registered hooks.
On table/base chain deletion, nf_tables will attempt to unregister
the hook again which yields a warn splat from the nftables core. |
