Security Vulnerabilities - CVEs Published In May 2026
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix oops when split header is enabled
For GMAC4, when split header is enabled, in some rare cases, the
hardware does not fill buf2 of the first descriptor with payload.
Thus we cannot assume buf2 is always fully filled if it is not
the last descriptor. Otherwise, the length of buf2 of the second
descriptor will be calculated wrong and cause an oops:
Unable to handle kernel paging request at virtual address ffff00019246bfc0
...
x2 : 0000000000000040 x1 : ffff00019246bfc0 x0 : ffff00009246c000
Call trace:
dcache_inval_poc+0x28/0x58 (P)
dma_direct_sync_single_for_cpu+0x38/0x6c
__dma_sync_single_for_cpu+0x34/0x6c
stmmac_napi_poll_rx+0x8f0/0xb60
__napi_poll.constprop.0+0x30/0x144
net_rx_action+0x160/0x274
handle_softirqs+0x1b8/0x1fc
...
To fix this, the PL bit-field in RDES3 register is used for all
descriptors, whether it is the last descriptor or not.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
tpm: tpm_i2c_infineon: Fix locality leak on get_burstcount() failure
get_burstcount() can return -EBUSY on timeout. When this happens, the
function returns directly without releasing the locality that was
acquired at the beginning of tpm_tis_i2c_send().
Use goto out_err to ensure proper cleanup when get_burstcount() fails.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix e4b bitmap inconsistency reports
A bitmap inconsistency issue was observed during stress tests under
mixed huge-page workloads. Ext4 reported multiple e4b bitmap check
failures like:
ext4_mb_complex_scan_group:2508: group 350, 8179 free clusters as
per group info. But got 8192 blocks
Analysis and experimentation confirmed that the issue is caused by a
race condition between page migration and bitmap modification. Although
this timing window is extremely narrow, it is still hit in practice:
folio_lock ext4_mb_load_buddy
__migrate_folio
check ref count
folio_mc_copy __filemap_get_folio
folio_try_get(folio)
......
mb_mark_used
ext4_mb_unload_buddy
__folio_migrate_mapping
folio_ref_freeze
folio_unlock
The root cause of this issue is that the fast path of load_buddy only
increments the folio's reference count, which is insufficient to prevent
concurrent folio migration. We observed that the folio migration process
acquires the folio lock. Therefore, we can determine whether to take the
fast path in load_buddy by checking the lock status. If the folio is
locked, we opt for the slow path (which acquires the lock) to close this
concurrency window.
Additionally, this change addresses the following issues:
When the DOUBLE_CHECK macro is enabled to inspect bitmap-related
issues, the following error may be triggered:
corruption in group 324 at byte 784(6272): f in copy != ff on
disk/prealloc
Analysis reveals that this is a false positive. There is a specific race
window where the bitmap and the group descriptor become momentarily
inconsistent, leading to this error report:
ext4_mb_load_buddy ext4_mb_load_buddy
__filemap_get_folio(create|lock)
folio_lock
ext4_mb_init_cache
folio_mark_uptodate
__filemap_get_folio(no lock)
......
mb_mark_used
mb_mark_used_double
mb_cmp_bitmaps
mb_set_bits(e4b->bd_bitmap)
folio_unlock
The original logic assumed that since mb_cmp_bitmaps is called when the
bitmap is newly loaded from disk, the folio lock would be sufficient to
prevent concurrent access. However, this overlooks a specific race
condition: if another process attempts to load buddy and finds the folio
is already in an uptodate state, it will immediately begin using it without
holding folio lock.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
erofs: fix inline data read failure for ztailpacking pclusters
Compressed folios for ztailpacking pclusters must be valid before adding
these pclusters to I/O chains. Otherwise, z_erofs_decompress_pcluster()
may assume they are already valid and then trigger a NULL pointer
dereference.
It is somewhat hard to reproduce because the inline data is in the same
block as the tail of the compressed indexes, which are usually read just
before. However, it may still happen if a fatal signal arrives while
read_mapping_folio() is running, as shown below:
erofs: (device dm-1): z_erofs_pcluster_begin: failed to get inline data -4
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
...
pc : z_erofs_decompress_queue+0x4c8/0xa14
lr : z_erofs_decompress_queue+0x160/0xa14
sp : ffffffc08b3eb3a0
x29: ffffffc08b3eb570 x28: ffffffc08b3eb418 x27: 0000000000001000
x26: ffffff8086ebdbb8 x25: ffffff8086ebdbb8 x24: 0000000000000001
x23: 0000000000000008 x22: 00000000fffffffb x21: dead000000000700
x20: 00000000000015e7 x19: ffffff808babb400 x18: ffffffc089edc098
x17: 00000000c006287d x16: 00000000c006287d x15: 0000000000000004
x14: ffffff80ba8f8000 x13: 0000000000000004 x12: 00000006589a77c9
x11: 0000000000000015 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : ffffffffffffffe0 x3 : 0000000000000020
x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
z_erofs_decompress_queue+0x4c8/0xa14
z_erofs_runqueue+0x908/0x97c
z_erofs_read_folio+0x128/0x228
filemap_read_folio+0x68/0x128
filemap_get_pages+0x44c/0x8b4
filemap_read+0x12c/0x5b8
generic_file_read_iter+0x4c/0x15c
do_iter_readv_writev+0x188/0x1e0
vfs_iter_read+0xac/0x1a4
backing_file_read_iter+0x170/0x34c
ovl_read_iter+0xf0/0x140
vfs_read+0x28c/0x344
ksys_read+0x80/0xf0
__arm64_sys_read+0x24/0x34
invoke_syscall+0x60/0x114
el0_svc_common+0x88/0xe4
do_el0_svc+0x24/0x30
el0_svc+0x40/0xa8
el0t_64_sync_handler+0x70/0xbc
el0t_64_sync+0x1bc/0x1c0
Fix this by reading the inline data before allocating and adding
the pclusters to the I/O chains.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Clear Present bit before tearing down context entry
When tearing down a context entry, the current implementation zeros the
entire 128-bit entry using multiple 64-bit writes. This creates a window
where the hardware can fetch a "torn" entry — where some fields are
already zeroed while the 'Present' bit is still set — leading to
unpredictable behavior or spurious faults.
While x86 provides strong write ordering, the compiler may reorder writes
to the two 64-bit halves of the context entry. Even without compiler
reordering, the hardware fetch is not guaranteed to be atomic with
respect to multiple CPU writes.
Align with the "Guidance to Software for Invalidations" in the VT-d spec
(Section 6.5.3.3) by implementing the recommended ownership handshake:
1. Clear only the 'Present' (P) bit of the context entry first to
signal the transition of ownership from hardware to software.
2. Use dma_wmb() to ensure the cleared bit is visible to the IOMMU.
3. Perform the required cache and context-cache invalidation to ensure
hardware no longer has cached references to the entry.
4. Fully zero out the entry only after the invalidation is complete.
Also, add a dma_wmb() to context_set_present() to ensure the entry
is fully initialized before the 'Present' bit becomes visible.
CVSS Score
7.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix race condition during PASID entry replacement
The Intel VT-d PASID table entry is 512 bits (64 bytes). When replacing
an active PASID entry (e.g., during domain replacement), the current
implementation calculates a new entry on the stack and copies it to the
table using a single structure assignment.
struct pasid_entry *pte, new_pte;
pte = intel_pasid_get_entry(dev, pasid);
pasid_pte_config_first_level(iommu, &new_pte, ...);
*pte = new_pte;
Because the hardware may fetch the 512-bit PASID entry in multiple
128-bit chunks, updating the entire entry while it is active (Present
bit set) risks a "torn" read. In this scenario, the IOMMU hardware
could observe an inconsistent state — partially new data and partially
old data — leading to unpredictable behavior or spurious faults.
Fix this by removing the unsafe "replace" helpers and following the
"clear-then-update" flow, which ensures the Present bit is cleared and
the required invalidation handshake is completed before the new
configuration is applied.
CVSS Score
8.8
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
power: supply: ab8500: Fix use-after-free in power_supply_changed()
Using the `devm_` variant for requesting IRQ _before_ the `devm_`
variant for allocating/registering the `power_supply` handle, means that
the `power_supply` handle will be deallocated/unregistered _before_ the
interrupt handler (since `devm_` naturally deallocates in reverse
allocation order). This means that during removal, there is a race
condition where an interrupt can fire just _after_ the `power_supply`
handle has been freed, *but* just _before_ the corresponding
unregistration of the IRQ handler has run.
This will lead to the IRQ handler calling `power_supply_changed()` with
a freed `power_supply` handle. Which usually crashes the system or
otherwise silently corrupts the memory...
Note that there is a similar situation which can also happen during
`probe()`; the possibility of an interrupt firing _before_ registering
the `power_supply` handle. This would then lead to the nasty situation
of using the `power_supply` handle *uninitialized* in
`power_supply_changed()`.
Commit 1c1f13a006ed ("power: supply: ab8500: Move to componentized
binding") introduced this issue during a refactorization. Fix this racy
use-after-free by making sure the IRQ is requested _after_ the
registration of the `power_supply` handle.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Hold mm structure across iommu_sva_unbind_device()
Some tests trigger a crash in iommu_sva_unbind_device() due to
accessing iommu_mm after the associated mm structure has been
freed.
Fix this by taking an explicit reference to the mm structure
after successfully binding the device, and releasing it only
after the device is unbound. This ensures the mm remains valid
for the entire SVA bind/unbind lifetime.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix tcx/netkit detach permissions when prog fd isn't given
This commit fixes a security issue where BPF_PROG_DETACH on tcx or
netkit devices could be executed by any user when no program fd was
provided, bypassing permission checks. The fix adds a capability
check for CAP_NET_ADMIN or CAP_SYS_ADMIN in this case.
CVSS Score
7.3
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
bpf: Preserve id of register in sync_linked_regs()
sync_linked_regs() copies the id of known_reg to reg when propagating
bounds of known_reg to reg using the off of known_reg, but when
known_reg was linked to reg like:
known_reg = reg ; both known_reg and reg get same id
known_reg += 4 ; known_reg gets off = 4, and its id gets BPF_ADD_CONST
now when a call to sync_linked_regs() happens, let's say with the following:
if known_reg >= 10 goto pc+2
known_reg's new bounds are propagated to reg but now reg gets
BPF_ADD_CONST from the copy.
This means if another link to reg is created like:
another_reg = reg ; another_reg should get the id of reg but
assign_scalar_id_before_mov() sees
BPF_ADD_CONST on reg and assigns a new id to it.
As reg has a new id now, known_reg's link to reg is broken. If we find
new bounds for known_reg, they will not be propagated to reg.
This can be seen in the selftest added in the next commit:
0: (85) call bpf_get_prandom_u32#7 ; R0=scalar()
1: (57) r0 &= 255 ; R0=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff))
2: (bf) r1 = r0 ; R0=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff)) R1=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff))
3: (07) r1 += 4 ; R1=scalar(id=1+4,smin=umin=smin32=umin32=4,smax=umax=smax32=umax32=259,var_off=(0x0; 0x1ff))
4: (a5) if r1 < 0xa goto pc+4 ; R1=scalar(id=1+4,smin=umin=smin32=umin32=10,smax=umax=smax32=umax32=259,var_off=(0x0; 0x1ff))
5: (bf) r2 = r0 ; R0=scalar(id=2,smin=umin=smin32=umin32=6,smax=umax=smax32=umax32=255) R2=scalar(id=2,smin=umin=smin32=umin32=6,smax=umax=smax32=umax32=255)
6: (a5) if r1 < 0xe goto pc+2 ; R1=scalar(id=1+4,smin=umin=smin32=umin32=14,smax=umax=smax32=umax32=259,var_off=(0x0; 0x1ff))
7: (35) if r0 >= 0xa goto pc+1 ; R0=scalar(id=2,smin=umin=smin32=umin32=6,smax=umax=smax32=umax32=9,var_off=(0x0; 0xf))
8: (37) r0 /= 0
div by zero
When 4 is verified, r1's bounds are propagated to r0 but r0 also gets
BPF_ADD_CONST (bug).
When 5 is verified, r0 gets a new id (2) and its link with r1 is broken.
After 6 we know r1 has bounds [14, 259] and therefore r0 should have
bounds [10, 255], therefore the branch at 7 is always taken. But because
r0's id was changed to 2, r1's new bounds are not propagated to r0.
The verifier still thinks r0 has bounds [6, 255] before 7 and execution
can reach div by zero.
Fix this by preserving id in sync_linked_regs() like off and subreg_def.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-05-27