Linux: >> Linux Kernel >> 2.6.39 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: use two-phase skb reclamation in ieee80211_do_stop()
Since '__dev_queue_xmit()' should be called with interrupts enabled,
the following backtrace:
ieee80211_do_stop()
...
spin_lock_irqsave(&local->queue_stop_reason_lock, flags)
...
ieee80211_free_txskb()
ieee80211_report_used_skb()
ieee80211_report_ack_skb()
cfg80211_mgmt_tx_status_ext()
nl80211_frame_tx_status()
genlmsg_multicast_netns()
genlmsg_multicast_netns_filtered()
nlmsg_multicast_filtered()
netlink_broadcast_filtered()
do_one_broadcast()
netlink_broadcast_deliver()
__netlink_sendskb()
netlink_deliver_tap()
__netlink_deliver_tap_skb()
dev_queue_xmit()
__dev_queue_xmit() ; with IRQS disabled
...
spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags)
issues the warning (as reported by syzbot reproducer):
WARNING: CPU: 2 PID: 5128 at kernel/softirq.c:362 __local_bh_enable_ip+0xc3/0x120
Fix this by implementing a two-phase skb reclamation in
'ieee80211_do_stop()', where actual work is performed
outside of a section with interrupts disabled.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential null-ptr-deref in nilfs_btree_insert()
Patch series "nilfs2: fix potential issues with empty b-tree nodes".
This series addresses three potential issues with empty b-tree nodes that
can occur with corrupted filesystem images, including one recently
discovered by syzbot.
This patch (of 3):
If a b-tree is broken on the device, and the b-tree height is greater than
2 (the level of the root node is greater than 1) even if the number of
child nodes of the b-tree root is 0, a NULL pointer dereference occurs in
nilfs_btree_prepare_insert(), which is called from nilfs_btree_insert().
This is because, when the number of child nodes of the b-tree root is 0,
nilfs_btree_do_lookup() does not set the block buffer head in any of
path[x].bp_bh, leaving it as the initial value of NULL, but if the level
of the b-tree root node is greater than 1, nilfs_btree_get_nonroot_node(),
which accesses the buffer memory of path[x].bp_bh, is called.
Fix this issue by adding a check to nilfs_btree_root_broken(), which
performs sanity checks when reading the root node from the device, to
detect this inconsistency.
Thanks to Lizhi Xu for trying to solve the bug and clarifying the cause
early on.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check link_res->hpo_dp_link_enc before using it
[WHAT & HOW]
Functions dp_enable_link_phy and dp_disable_link_phy can pass link_res
without initializing hpo_dp_link_enc and it is necessary to check for
null before dereferencing.
This fixes 2 FORWARD_NULL issues reported by Coverity.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Skip Recompute DSC Params if no Stream on Link
[why]
Encounter NULL pointer dereference uner mst + dsc setup.
BUG: kernel NULL pointer dereference, address: 0000000000000008
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 4 PID: 917 Comm: sway Not tainted 6.3.9-arch1-1 #1 124dc55df4f5272ccb409f39ef4872fc2b3376a2
Hardware name: LENOVO 20NKS01Y00/20NKS01Y00, BIOS R12ET61W(1.31 ) 07/28/2022
RIP: 0010:drm_dp_atomic_find_time_slots+0x5e/0x260 [drm_display_helper]
Code: 01 00 00 48 8b 85 60 05 00 00 48 63 80 88 00 00 00 3b 43 28 0f 8d 2e 01 00 00 48 8b 53 30 48 8d 04 80 48 8d 04 c2 48 8b 40 18 <48> 8>
RSP: 0018:ffff960cc2df77d8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8afb87e81280 RCX: 0000000000000224
RDX: ffff8afb9ee37c00 RSI: ffff8afb8da1a578 RDI: ffff8afb87e81280
RBP: ffff8afb83d67000 R08: 0000000000000001 R09: ffff8afb9652f850
R10: ffff960cc2df7908 R11: 0000000000000002 R12: 0000000000000000
R13: ffff8afb8d7688a0 R14: ffff8afb8da1a578 R15: 0000000000000224
FS: 00007f4dac35ce00(0000) GS:ffff8afe30b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000010ddc6000 CR4: 00000000003506e0
Call Trace:
<TASK>
? __die+0x23/0x70
? page_fault_oops+0x171/0x4e0
? plist_add+0xbe/0x100
? exc_page_fault+0x7c/0x180
? asm_exc_page_fault+0x26/0x30
? drm_dp_atomic_find_time_slots+0x5e/0x260 [drm_display_helper 0e67723696438d8e02b741593dd50d80b44c2026]
? drm_dp_atomic_find_time_slots+0x28/0x260 [drm_display_helper 0e67723696438d8e02b741593dd50d80b44c2026]
compute_mst_dsc_configs_for_link+0x2ff/0xa40 [amdgpu 62e600d2a75e9158e1cd0a243bdc8e6da040c054]
? fill_plane_buffer_attributes+0x419/0x510 [amdgpu 62e600d2a75e9158e1cd0a243bdc8e6da040c054]
compute_mst_dsc_configs_for_state+0x1e1/0x250 [amdgpu 62e600d2a75e9158e1cd0a243bdc8e6da040c054]
amdgpu_dm_atomic_check+0xecd/0x1190 [amdgpu 62e600d2a75e9158e1cd0a243bdc8e6da040c054]
drm_atomic_check_only+0x5c5/0xa40
drm_mode_atomic_ioctl+0x76e/0xbc0
[how]
dsc recompute should be skipped if no mode change detected on the new
request. If detected, keep checking whether the stream is already on
current state or not.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
vfs: fix race between evice_inodes() and find_inode()&iput()
Hi, all
Recently I noticed a bug[1] in btrfs, after digged it into
and I believe it'a race in vfs.
Let's assume there's a inode (ie ino 261) with i_count 1 is
called by iput(), and there's a concurrent thread calling
generic_shutdown_super().
cpu0: cpu1:
iput() // i_count is 1
->spin_lock(inode)
->dec i_count to 0
->iput_final() generic_shutdown_super()
->__inode_add_lru() ->evict_inodes()
// cause some reason[2] ->if (atomic_read(inode->i_count)) continue;
// return before // inode 261 passed the above check
// list_lru_add_obj() // and then schedule out
->spin_unlock()
// note here: the inode 261
// was still at sb list and hash list,
// and I_FREEING|I_WILL_FREE was not been set
btrfs_iget()
// after some function calls
->find_inode()
// found the above inode 261
->spin_lock(inode)
// check I_FREEING|I_WILL_FREE
// and passed
->__iget()
->spin_unlock(inode) // schedule back
->spin_lock(inode)
// check (I_NEW|I_FREEING|I_WILL_FREE) flags,
// passed and set I_FREEING
iput() ->spin_unlock(inode)
->spin_lock(inode) ->evict()
// dec i_count to 0
->iput_final()
->spin_unlock()
->evict()
Now, we have two threads simultaneously evicting
the same inode, which may trigger the BUG(inode->i_state & I_CLEAR)
statement both within clear_inode() and iput().
To fix the bug, recheck the inode->i_count after holding i_lock.
Because in the most scenarios, the first check is valid, and
the overhead of spin_lock() can be reduced.
If there is any misunderstanding, please let me know, thanks.
[1]: https://lore.kernel.org/linux-btrfs/000000000000eabe1d0619c48986@google.com/
[2]: The reason might be 1. SB_ACTIVE was removed or 2. mapping_shrinkable()
return false when I reproduced the bug.
CVSS Score
4.7
EPSS Score
0.0
Published
2024-10-21
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.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-15
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Avoid overflow from uint32_t to uint8_t
[WHAT & HOW]
dmub_rb_cmd's ramping_boundary has size of uint8_t and it is assigned
0xFFFF. Fix it by changing it to uint8_t with value of 0xFF.
This fixes 2 INTEGER_OVERFLOW issues reported by Coverity.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-09
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Remove register from DCN35 DMCUB diagnostic collection
[Why]
These registers should not be read from driver and triggering the
security violation when DMCUB work times out and diagnostics are
collected blocks Z8 entry.
[How]
Remove the register read from DCN35.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-09
In the Linux kernel, the following vulnerability has been resolved:
staging: iio: frequency: ad9834: Validate frequency parameter value
In ad9834_write_frequency() clk_get_rate() can return 0. In such case
ad9834_calc_freqreg() call will lead to division by zero. Checking
'if (fout > (clk_freq / 2))' doesn't protect in case of 'fout' is 0.
ad9834_write_frequency() is called from ad9834_write(), where fout is
taken from text buffer, which can contain any value.
Modify parameters checking.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-09
In the Linux kernel, the following vulnerability has been resolved:
spi: hisi-kunpeng: Add verification for the max_frequency provided by the firmware
If the value of max_speed_hz is 0, it may cause a division by zero
error in hisi_calc_effective_speed().
The value of max_speed_hz is provided by firmware.
Firmware is generally considered as a trusted domain. However, as
division by zero errors can cause system failure, for defense measure,
the value of max_speed is validated here. So 0 is regarded as invalid
and an error code is returned.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-09