Linux: >> Linux Kernel >> 6.6.48 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()
If track_pfn_copy() fails, we already added the dst VMA to the maple
tree. As fork() fails, we'll cleanup the maple tree, and stumble over
the dst VMA for which we neither performed any reservation nor copied
any page tables.
Consequently untrack_pfn() will see VM_PAT and try obtaining the
PAT information from the page table -- which fails because the page
table was not copied.
The easiest fix would be to simply clear the VM_PAT flag of the dst VMA
if track_pfn_copy() fails. However, the whole thing is about "simply"
clearing the VM_PAT flag is shaky as well: if we passed track_pfn_copy()
and performed a reservation, but copying the page tables fails, we'll
simply clear the VM_PAT flag, not properly undoing the reservation ...
which is also wrong.
So let's fix it properly: set the VM_PAT flag only if the reservation
succeeded (leaving it clear initially), and undo the reservation if
anything goes wrong while copying the page tables: clearing the VM_PAT
flag after undoing the reservation.
Note that any copied page table entries will get zapped when the VMA will
get removed later, after copy_page_range() succeeded; as VM_PAT is not set
then, we won't try cleaning VM_PAT up once more and untrack_pfn() will be
happy. Note that leaving these page tables in place without a reservation
is not a problem, as we are aborting fork(); this process will never run.
A reproducer can trigger this usually at the first try:
https://gitlab.com/davidhildenbrand/scratchspace/-/raw/main/reproducers/pat_fork.c
WARNING: CPU: 26 PID: 11650 at arch/x86/mm/pat/memtype.c:983 get_pat_info+0xf6/0x110
Modules linked in: ...
CPU: 26 UID: 0 PID: 11650 Comm: repro3 Not tainted 6.12.0-rc5+ #92
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:get_pat_info+0xf6/0x110
...
Call Trace:
<TASK>
...
untrack_pfn+0x52/0x110
unmap_single_vma+0xa6/0xe0
unmap_vmas+0x105/0x1f0
exit_mmap+0xf6/0x460
__mmput+0x4b/0x120
copy_process+0x1bf6/0x2aa0
kernel_clone+0xab/0x440
__do_sys_clone+0x66/0x90
do_syscall_64+0x95/0x180
Likely this case was missed in:
d155df53f310 ("x86/mm/pat: clear VM_PAT if copy_p4d_range failed")
... and instead of undoing the reservation we simply cleared the VM_PAT flag.
Keep the documentation of these functions in include/linux/pgtable.h,
one place is more than sufficient -- we should clean that up for the other
functions like track_pfn_remap/untrack_pfn separately.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
PCI: brcmstb: Fix error path after a call to regulator_bulk_get()
If the regulator_bulk_get() returns an error and no regulators
are created, we need to set their number to zero.
If we don't do this and the PCIe link up fails, a call to the
regulator_bulk_free() will result in a kernel panic.
While at it, print the error value, as we cannot return an error
upwards as the kernel will WARN() on an error from add_bus().
[kwilczynski: commit log, use comma in the message to match style with
other similar messages]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate l_tree_depth to avoid out-of-bounds access
The l_tree_depth field is 16-bit (__le16), but the actual maximum depth is
limited to OCFS2_MAX_PATH_DEPTH.
Add a check to prevent out-of-bounds access if l_tree_depth has an invalid
value, which may occur when reading from a corrupted mounted disk [1].
CVSS Score
7.1
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: Prevent integer overflow in hdr_first_de()
The "de_off" and "used" variables come from the disk so they both need to
check. The problem is that on 32bit systems if they're both greater than
UINT_MAX - 16 then the check does work as intended because of an integer
overflow.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: Fix a couple integer overflows on 32bit systems
On 32bit systems the "off + sizeof(struct NTFS_DE)" addition can
have an integer wrapping issue. Fix it by using size_add().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
vhost-scsi: Fix handling of multiple calls to vhost_scsi_set_endpoint
If vhost_scsi_set_endpoint is called multiple times without a
vhost_scsi_clear_endpoint between them, we can hit multiple bugs
found by Haoran Zhang:
1. Use-after-free when no tpgs are found:
This fixes a use after free that occurs when vhost_scsi_set_endpoint is
called more than once and calls after the first call do not find any
tpgs to add to the vs_tpg. When vhost_scsi_set_endpoint first finds
tpgs to add to the vs_tpg array match=true, so we will do:
vhost_vq_set_backend(vq, vs_tpg);
...
kfree(vs->vs_tpg);
vs->vs_tpg = vs_tpg;
If vhost_scsi_set_endpoint is called again and no tpgs are found
match=false so we skip the vhost_vq_set_backend call leaving the
pointer to the vs_tpg we then free via:
kfree(vs->vs_tpg);
vs->vs_tpg = vs_tpg;
If a scsi request is then sent we do:
vhost_scsi_handle_vq -> vhost_scsi_get_req -> vhost_vq_get_backend
which sees the vs_tpg we just did a kfree on.
2. Tpg dir removal hang:
This patch fixes an issue where we cannot remove a LIO/target layer
tpg (and structs above it like the target) dir due to the refcount
dropping to -1.
The problem is that if vhost_scsi_set_endpoint detects a tpg is already
in the vs->vs_tpg array or if the tpg has been removed so
target_depend_item fails, the undepend goto handler will do
target_undepend_item on all tpgs in the vs_tpg array dropping their
refcount to 0. At this time vs_tpg contains both the tpgs we have added
in the current vhost_scsi_set_endpoint call as well as tpgs we added in
previous calls which are also in vs->vs_tpg.
Later, when vhost_scsi_clear_endpoint runs it will do
target_undepend_item on all the tpgs in the vs->vs_tpg which will drop
their refcount to -1. Userspace will then not be able to remove the tpg
and will hang when it tries to do rmdir on the tpg dir.
3. Tpg leak:
This fixes a bug where we can leak tpgs and cause them to be
un-removable because the target name is overwritten when
vhost_scsi_set_endpoint is called multiple times but with different
target names.
The bug occurs if a user has called VHOST_SCSI_SET_ENDPOINT and setup
a vhost-scsi device to target/tpg mapping, then calls
VHOST_SCSI_SET_ENDPOINT again with a new target name that has tpgs we
haven't seen before (target1 has tpg1 but target2 has tpg2). When this
happens we don't teardown the old target tpg mapping and just overwrite
the target name and the vs->vs_tpg array. Later when we do
vhost_scsi_clear_endpoint, we are passed in either target1 or target2's
name and we will only match that target's tpgs when we loop over the
vs->vs_tpg. We will then return from the function without doing
target_undepend_item on the tpgs.
Because of all these bugs, it looks like being able to call
vhost_scsi_set_endpoint multiple times was never supported. The major
user, QEMU, already has checks to prevent this use case. So to fix the
issues, this patch prevents vhost_scsi_set_endpoint from being called
if it's already successfully added tpgs. To add, remove or change the
tpg config or target name, you must do a vhost_scsi_clear_endpoint
first.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix mlx5_poll_one() cur_qp update flow
When cur_qp isn't NULL, in order to avoid fetching the QP from
the radix tree again we check if the next cqe QP is identical to
the one we already have.
The bug however is that we are checking if the QP is identical by
checking the QP number inside the CQE against the QP number inside the
mlx5_ib_qp, but that's wrong since the QP number from the CQE is from
FW so it should be matched against mlx5_core_qp which is our FW QP
number.
Otherwise we could use the wrong QP when handling a CQE which could
cause the kernel trace below.
This issue is mainly noticeable over QPs 0 & 1, since for now they are
the only QPs in our driver whereas the QP number inside mlx5_ib_qp
doesn't match the QP number inside mlx5_core_qp.
BUG: kernel NULL pointer dereference, address: 0000000000000012
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP
CPU: 0 UID: 0 PID: 7927 Comm: kworker/u62:1 Not tainted 6.14.0-rc3+ #189
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: ib-comp-unb-wq ib_cq_poll_work [ib_core]
RIP: 0010:mlx5_ib_poll_cq+0x4c7/0xd90 [mlx5_ib]
Code: 03 00 00 8d 58 ff 21 cb 66 39 d3 74 39 48 c7 c7 3c 89 6e a0 0f b7 db e8 b7 d2 b3 e0 49 8b 86 60 03 00 00 48 c7 c7 4a 89 6e a0 <0f> b7 5c 98 02 e8 9f d2 b3 e0 41 0f b7 86 78 03 00 00 83 e8 01 21
RSP: 0018:ffff88810511bd60 EFLAGS: 00010046
RAX: 0000000000000010 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88885fa1b3c0 RDI: ffffffffa06e894a
RBP: 00000000000000b0 R08: 0000000000000000 R09: ffff88810511bc10
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88810d593000
R13: ffff88810e579108 R14: ffff888105146000 R15: 00000000000000b0
FS: 0000000000000000(0000) GS:ffff88885fa00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000012 CR3: 00000001077e6001 CR4: 0000000000370eb0
Call Trace:
<TASK>
? __die+0x20/0x60
? page_fault_oops+0x150/0x3e0
? exc_page_fault+0x74/0x130
? asm_exc_page_fault+0x22/0x30
? mlx5_ib_poll_cq+0x4c7/0xd90 [mlx5_ib]
__ib_process_cq+0x5a/0x150 [ib_core]
ib_cq_poll_work+0x31/0x90 [ib_core]
process_one_work+0x169/0x320
worker_thread+0x288/0x3a0
? work_busy+0xb0/0xb0
kthread+0xd7/0x1f0
? kthreads_online_cpu+0x130/0x130
? kthreads_online_cpu+0x130/0x130
ret_from_fork+0x2d/0x50
? kthreads_online_cpu+0x130/0x130
ret_from_fork_asm+0x11/0x20
</TASK>
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
fs/9p: fix NULL pointer dereference on mkdir
When a 9p tree was mounted with option 'posixacl', parent directory had a
default ACL set for its subdirectories, e.g.:
setfacl -m default:group:simpsons:rwx parentdir
then creating a subdirectory crashed 9p client, as v9fs_fid_add() call in
function v9fs_vfs_mkdir_dotl() sets the passed 'fid' pointer to NULL
(since dafbe689736) even though the subsequent v9fs_set_create_acl() call
expects a valid non-NULL 'fid' pointer:
[ 37.273191] BUG: kernel NULL pointer dereference, address: 0000000000000000
...
[ 37.322338] Call Trace:
[ 37.323043] <TASK>
[ 37.323621] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434)
[ 37.324448] ? page_fault_oops (arch/x86/mm/fault.c:714)
[ 37.325532] ? search_module_extables (kernel/module/main.c:3733)
[ 37.326742] ? p9_client_walk (net/9p/client.c:1165) 9pnet
[ 37.328006] ? search_bpf_extables (kernel/bpf/core.c:804)
[ 37.329142] ? exc_page_fault (./arch/x86/include/asm/paravirt.h:686 arch/x86/mm/fault.c:1488 arch/x86/mm/fault.c:1538)
[ 37.330196] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:574)
[ 37.331330] ? p9_client_walk (net/9p/client.c:1165) 9pnet
[ 37.332562] ? v9fs_fid_xattr_get (fs/9p/xattr.c:30) 9p
[ 37.333824] v9fs_fid_xattr_set (fs/9p/fid.h:23 fs/9p/xattr.c:121) 9p
[ 37.335077] v9fs_set_acl (fs/9p/acl.c:276) 9p
[ 37.336112] v9fs_set_create_acl (fs/9p/acl.c:307) 9p
[ 37.337326] v9fs_vfs_mkdir_dotl (fs/9p/vfs_inode_dotl.c:411) 9p
[ 37.338590] vfs_mkdir (fs/namei.c:4313)
[ 37.339535] do_mkdirat (fs/namei.c:4336)
[ 37.340465] __x64_sys_mkdir (fs/namei.c:4354)
[ 37.341455] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 37.342447] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Fix this by simply swapping the sequence of these two calls in
v9fs_vfs_mkdir_dotl(), i.e. calling v9fs_set_create_acl() before
v9fs_fid_add().
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
spufs: fix a leak in spufs_create_context()
Leak fixes back in 2008 missed one case - if we are trying to set affinity
and spufs_mkdir() fails, we need to drop the reference to neighbor.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16
In the Linux kernel, the following vulnerability has been resolved:
spufs: fix gang directory lifetimes
prior to "[POWERPC] spufs: Fix gang destroy leaks" we used to have
a problem with gang lifetimes - creation of a gang returns opened
gang directory, which normally gets removed when that gets closed,
but if somebody has created a context belonging to that gang and
kept it alive until the gang got closed, removal failed and we
ended up with a leak.
Unfortunately, it had been fixed the wrong way. Dentry of gang
directory was no longer pinned, and rmdir on close was gone.
One problem was that failure of open kept calling simple_rmdir()
as cleanup, which meant an unbalanced dput(). Another bug was
in the success case - gang creation incremented link count on
root directory, but that was no longer undone when gang got
destroyed.
Fix consists of
* reverting the commit in question
* adding a counter to gang, protected by ->i_rwsem
of gang directory inode.
* having it set to 1 at creation time, dropped
in both spufs_dir_close() and spufs_gang_close() and bumped
in spufs_create_context(), provided that it's not 0.
* using simple_recursive_removal() to take the gang
directory out when counter reaches zero.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-16