In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dpu: Add mutex lock in control vblank irq
Add a mutex lock to control vblank irq to synchronize vblank
enable/disable operations happening from different threads to prevent
race conditions while registering/unregistering the vblank irq callback.
v4: -Removed vblank_ctl_lock from dpu_encoder_virt, so it is only a
parameter of dpu_encoder_phys.
-Switch from atomic refcnt to a simple int counter as mutex has
now been added
v3: Mistakenly did not change wording in last version. It is done now.
v2: Slightly changed wording of commit message
Patchwork: https://patchwork.freedesktop.org/patch/571854/
In the Linux kernel, the following vulnerability has been resolved:
IB/ipoib: Fix mcast list locking
Releasing the `priv->lock` while iterating the `priv->multicast_list` in
`ipoib_mcast_join_task()` opens a window for `ipoib_mcast_dev_flush()` to
remove the items while in the middle of iteration. If the mcast is removed
while the lock was dropped, the for loop spins forever resulting in a hard
lockup (as was reported on RHEL 4.18.0-372.75.1.el8_6 kernel):
Task A (kworker/u72:2 below) | Task B (kworker/u72:0 below)
-----------------------------------+-----------------------------------
ipoib_mcast_join_task(work) | ipoib_ib_dev_flush_light(work)
spin_lock_irq(&priv->lock) | __ipoib_ib_dev_flush(priv, ...)
list_for_each_entry(mcast, | ipoib_mcast_dev_flush(dev = priv->dev)
&priv->multicast_list, list) |
ipoib_mcast_join(dev, mcast) |
spin_unlock_irq(&priv->lock) |
| spin_lock_irqsave(&priv->lock, flags)
| list_for_each_entry_safe(mcast, tmcast,
| &priv->multicast_list, list)
| list_del(&mcast->list);
| list_add_tail(&mcast->list, &remove_list)
| spin_unlock_irqrestore(&priv->lock, flags)
spin_lock_irq(&priv->lock) |
| ipoib_mcast_remove_list(&remove_list)
(Here, `mcast` is no longer on the | list_for_each_entry_safe(mcast, tmcast,
`priv->multicast_list` and we keep | remove_list, list)
spinning on the `remove_list` of | >>> wait_for_completion(&mcast->done)
the other thread which is blocked |
and the list is still valid on |
it's stack.)
Fix this by keeping the lock held and changing to GFP_ATOMIC to prevent
eventual sleeps.
Unfortunately we could not reproduce the lockup and confirm this fix but
based on the code review I think this fix should address such lockups.
crash> bc 31
PID: 747 TASK: ff1c6a1a007e8000 CPU: 31 COMMAND: "kworker/u72:2"
--
[exception RIP: ipoib_mcast_join_task+0x1b1]
RIP: ffffffffc0944ac1 RSP: ff646f199a8c7e00 RFLAGS: 00000002
RAX: 0000000000000000 RBX: ff1c6a1a04dc82f8 RCX: 0000000000000000
work (&priv->mcast_task{,.work})
RDX: ff1c6a192d60ac68 RSI: 0000000000000286 RDI: ff1c6a1a04dc8000
&mcast->list
RBP: ff646f199a8c7e90 R8: ff1c699980019420 R9: ff1c6a1920c9a000
R10: ff646f199a8c7e00 R11: ff1c6a191a7d9800 R12: ff1c6a192d60ac00
mcast
R13: ff1c6a1d82200000 R14: ff1c6a1a04dc8000 R15: ff1c6a1a04dc82d8
dev priv (&priv->lock) &priv->multicast_list (aka head)
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
--- <NMI exception stack> ---
#5 [ff646f199a8c7e00] ipoib_mcast_join_task+0x1b1 at ffffffffc0944ac1 [ib_ipoib]
#6 [ff646f199a8c7e98] process_one_work+0x1a7 at ffffffff9bf10967
crash> rx ff646f199a8c7e68
ff646f199a8c7e68: ff1c6a1a04dc82f8 <<< work = &priv->mcast_task.work
crash> list -hO ipoib_dev_priv.multicast_list ff1c6a1a04dc8000
(empty)
crash> ipoib_dev_priv.mcast_task.work.func,mcast_mutex.owner.counter ff1c6a1a04dc8000
mcast_task.work.func = 0xffffffffc0944910 <ipoib_mcast_join_task>,
mcast_mutex.owner.counter = 0xff1c69998efec000
crash> b 8
PID: 8 TASK: ff1c69998efec000 CPU: 33 COMMAND: "kworker/u72:0"
--
#3 [ff646f1980153d50] wait_for_completion+0x96 at ffffffff9c7d7646
#4 [ff646f1980153d90] ipoib_mcast_remove_list+0x56 at ffffffffc0944dc6 [ib_ipoib]
#5 [ff646f1980153de8] ipoib_mcast_dev_flush+0x1a7 at ffffffffc09455a7 [ib_ipoib]
#6 [ff646f1980153e58] __ipoib_ib_dev_flush+0x1a4 at ffffffffc09431a4 [ib_ipoib]
#7 [ff
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to tag gcing flag on page during block migration
It needs to add missing gcing flag on page during block migration,
in order to garantee migrated data be persisted during checkpoint,
otherwise out-of-order persistency between data and node may cause
data corruption after SPOR.
Similar issue was fixed by commit 2d1fe8a86bf5 ("f2fs: fix to tag
gcing flag on page during file defragment").
In the Linux kernel, the following vulnerability has been resolved:
ceph: fix deadlock or deadcode of misusing dget()
The lock order is incorrect between denty and its parent, we should
always make sure that the parent get the lock first.
But since this deadcode is never used and the parent dir will always
be set from the callers, let's just remove it.
In the Linux kernel, the following vulnerability has been resolved:
tun: avoid double free in tun_free_netdev
Avoid double free in tun_free_netdev() by moving the
dev->tstats and tun->security allocs to a new ndo_init routine
(tun_net_init()) that will be called by register_netdevice().
ndo_init is paired with the desctructor (tun_free_netdev()),
so if there's an error in register_netdevice() the destructor
will handle the frees.
BUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605
CPU: 0 PID: 25750 Comm: syz-executor416 Not tainted 5.16.0-rc2-syzk #1
Hardware name: Red Hat KVM, BIOS
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106
print_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:247
kasan_report_invalid_free+0x55/0x80 mm/kasan/report.c:372
____kasan_slab_free mm/kasan/common.c:346 [inline]
__kasan_slab_free+0x107/0x120 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:1723 [inline]
slab_free_freelist_hook mm/slub.c:1749 [inline]
slab_free mm/slub.c:3513 [inline]
kfree+0xac/0x2d0 mm/slub.c:4561
selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605
security_tun_dev_free_security+0x4f/0x90 security/security.c:2342
tun_free_netdev+0xe6/0x150 drivers/net/tun.c:2215
netdev_run_todo+0x4df/0x840 net/core/dev.c:10627
rtnl_unlock+0x13/0x20 net/core/rtnetlink.c:112
__tun_chr_ioctl+0x80c/0x2870 drivers/net/tun.c:3302
tun_chr_ioctl+0x2f/0x40 drivers/net/tun.c:3311
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: mediatek: fix global-out-of-bounds issue
When eint virtual eint number is greater than gpio number,
it maybe produce 'desc[eint_n]' size globle-out-of-bounds issue.
In the Linux kernel, the following vulnerability has been resolved:
phonet/pep: refuse to enable an unbound pipe
This ioctl() implicitly assumed that the socket was already bound to
a valid local socket name, i.e. Phonet object. If the socket was not
bound, two separate problems would occur:
1) We'd send an pipe enablement request with an invalid source object.
2) Later socket calls could BUG on the socket unexpectedly being
connected yet not bound to a valid object.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: remove BUG() after failure to insert delayed dir index item
Instead of calling BUG() when we fail to insert a delayed dir index item
into the delayed node's tree, we can just release all the resources we
have allocated/acquired before and return the error to the caller. This is
fine because all existing call chains undo anything they have done before
calling btrfs_insert_delayed_dir_index() or BUG_ON (when creating pending
snapshots in the transaction commit path).
So remove the BUG() call and do proper error handling.
This relates to a syzbot report linked below, but does not fix it because
it only prevents hitting a BUG(), it does not fix the issue where somehow
we attempt to use twice the same index number for different index items.
In the Linux kernel, the following vulnerability has been resolved:
arm64: dts: qcom: sdm845-db845c: Mark cont splash memory region as reserved
Adding a reserved memory region for the framebuffer memory
(the splash memory region set up by the bootloader).
It fixes a kernel panic (arm-smmu: Unhandled context fault
at this particular memory region) reported on DB845c running
v5.10.y.
In the Linux kernel, the following vulnerability has been resolved:
ceph: drop messages from MDS when unmounting
When unmounting all the dirty buffers will be flushed and after
the last osd request is finished the last reference of the i_count
will be released. Then it will flush the dirty cap/snap to MDSs,
and the unmounting won't wait the possible acks, which will ihold
the inodes when updating the metadata locally but makes no sense
any more, of this. This will make the evict_inodes() to skip these
inodes.
If encrypt is enabled the kernel generate a warning when removing
the encrypt keys when the skipped inodes still hold the keyring:
WARNING: CPU: 4 PID: 168846 at fs/crypto/keyring.c:242 fscrypt_destroy_keyring+0x7e/0xd0
CPU: 4 PID: 168846 Comm: umount Tainted: G S 6.1.0-rc5-ceph-g72ead199864c #1
Hardware name: Supermicro SYS-5018R-WR/X10SRW-F, BIOS 2.0 12/17/2015
RIP: 0010:fscrypt_destroy_keyring+0x7e/0xd0
RSP: 0018:ffffc9000b277e28 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff88810d52ac00 RCX: ffff88810b56aa00
RDX: 0000000080000000 RSI: ffffffff822f3a09 RDI: ffff888108f59000
RBP: ffff8881d394fb88 R08: 0000000000000028 R09: 0000000000000000
R10: 0000000000000001 R11: 11ff4fe6834fcd91 R12: ffff8881d394fc40
R13: ffff888108f59000 R14: ffff8881d394f800 R15: 0000000000000000
FS: 00007fd83f6f1080(0000) GS:ffff88885fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f918d417000 CR3: 000000017f89a005 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
generic_shutdown_super+0x47/0x120
kill_anon_super+0x14/0x30
ceph_kill_sb+0x36/0x90 [ceph]
deactivate_locked_super+0x29/0x60
cleanup_mnt+0xb8/0x140
task_work_run+0x67/0xb0
exit_to_user_mode_prepare+0x23d/0x240
syscall_exit_to_user_mode+0x25/0x60
do_syscall_64+0x40/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd83dc39e9b
Later the kernel will crash when iput() the inodes and dereferencing
the "sb->s_master_keys", which has been released by the
generic_shutdown_super().