| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Fix mmap write lock not release
If mmap write lock is taken while draining retry fault, mmap write lock
is not released because svm_range_restore_pages calls mmap_read_unlock
then returns. This causes deadlock and system hangs later because mmap
read or write lock cannot be taken.
Downgrade mmap write lock to read lock if draining retry fault fix this
bug. |
| In the Linux kernel, the following vulnerability has been resolved:
amd/amdkfd: resolve a race in amdgpu_amdkfd_device_fini_sw
There is race in amdgpu_amdkfd_device_fini_sw and interrupt.
if amdgpu_amdkfd_device_fini_sw run in b/w kfd_cleanup_nodes and
kfree(kfd), and KGD interrupt generated.
kernel panic log:
BUG: kernel NULL pointer dereference, address: 0000000000000098
amdgpu 0000:c8:00.0: amdgpu: Requesting 4 partitions through PSP
PGD d78c68067 P4D d78c68067
kfd kfd: amdgpu: Allocated 3969056 bytes on gart
PUD 1465b8067 PMD @
Oops: @002 [#1] SMP NOPTI
kfd kfd: amdgpu: Total number of KFD nodes to be created: 4
CPU: 115 PID: @ Comm: swapper/115 Kdump: loaded Tainted: G S W OE K
RIP: 0010:_raw_spin_lock_irqsave+0x12/0x40
Code: 89 e@ 41 5c c3 cc cc cc cc 66 66 2e Of 1f 84 00 00 00 00 00 OF 1f 40 00 Of 1f 44% 00 00 41 54 9c 41 5c fa 31 cO ba 01 00 00 00 <fO> OF b1 17 75 Ba 4c 89 e@ 41 Sc
89 c6 e8 07 38 5d
RSP: 0018: ffffc90@1a6b0e28 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000018
0000000000000001 RSI: ffff8883bb623e00 RDI: 0000000000000098
ffff8883bb000000 RO8: ffff888100055020 ROO: ffff888100055020
0000000000000000 R11: 0000000000000000 R12: 0900000000000002
ffff888F2b97da0@ R14: @000000000000098 R15: ffff8883babdfo00
CS: 010 DS: 0000 ES: 0000 CRO: 0000000080050033
CR2: 0000000000000098 CR3: 0000000e7cae2006 CR4: 0000000002770ce0
0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
0000000000000000 DR6: 00000000fffeO7FO DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<IRQ>
kgd2kfd_interrupt+@x6b/0x1f@ [amdgpu]
? amdgpu_fence_process+0xa4/0x150 [amdgpu]
kfd kfd: amdgpu: Node: 0, interrupt_bitmap: 3 YcpxFl Rant tErace
amdgpu_irq_dispatch+0x165/0x210 [amdgpu]
amdgpu_ih_process+0x80/0x100 [amdgpu]
amdgpu: Virtual CRAT table created for GPU
amdgpu_irq_handler+0x1f/@x60 [amdgpu]
__handle_irq_event_percpu+0x3d/0x170
amdgpu: Topology: Add dGPU node [0x74a2:0x1002]
handle_irq_event+0x5a/@xcO
handle_edge_irq+0x93/0x240
kfd kfd: amdgpu: KFD node 1 partition @ size 49148M
asm_call_irq_on_stack+0xf/@x20
</IRQ>
common_interrupt+0xb3/0x130
asm_common_interrupt+0x1le/0x40
5.10.134-010.a1i5000.a18.x86_64 #1 |
| In the Linux kernel, the following vulnerability has been resolved:
exfat: fix improper check of dentry.stream.valid_size
We found an infinite loop bug in the exFAT file system that can lead to a
Denial-of-Service (DoS) condition. When a dentry in an exFAT filesystem is
malformed, the following system calls — SYS_openat, SYS_ftruncate, and
SYS_pwrite64 — can cause the kernel to hang.
Root cause analysis shows that the size validation code in exfat_find()
does not check whether dentry.stream.valid_size is negative. As a result,
the system calls mentioned above can succeed and eventually trigger the DoS
issue.
This patch adds a check for negative dentry.stream.valid_size to prevent
this vulnerability. |
| In the Linux kernel, the following vulnerability has been resolved:
smb/server: fix possible memory leak in smb2_read()
Memory leak occurs when ksmbd_vfs_read() fails.
Fix this by adding the missing kvfree(). |
| In the Linux kernel, the following vulnerability has been resolved:
smb/server: fix possible refcount leak in smb2_sess_setup()
Reference count of ksmbd_session will leak when session need reconnect.
Fix this by adding the missing ksmbd_user_session_put(). |
| In the Linux kernel, the following vulnerability has been resolved:
drm/v3d: Avoid NULL pointer dereference in `v3d_job_update_stats()`
The following kernel Oops was recently reported by Mesa CI:
[ 800.139824] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000588
[ 800.148619] Mem abort info:
[ 800.151402] ESR = 0x0000000096000005
[ 800.155141] EC = 0x25: DABT (current EL), IL = 32 bits
[ 800.160444] SET = 0, FnV = 0
[ 800.163488] EA = 0, S1PTW = 0
[ 800.166619] FSC = 0x05: level 1 translation fault
[ 800.171487] Data abort info:
[ 800.174357] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
[ 800.179832] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 800.184873] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 800.190176] user pgtable: 4k pages, 39-bit VAs, pgdp=00000001014c2000
[ 800.196607] [0000000000000588] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
[ 800.205305] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
[ 800.211564] Modules linked in: vc4 snd_soc_hdmi_codec drm_display_helper v3d cec gpu_sched drm_dma_helper drm_shmem_helper drm_kms_helper drm drm_panel_orientation_quirks snd_soc_core snd_compress snd_pcm_dmaengine snd_pcm i2c_brcmstb snd_timer snd backlight
[ 800.234448] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.25+rpt-rpi-v8 #1 Debian 1:6.12.25-1+rpt1
[ 800.244182] Hardware name: Raspberry Pi 4 Model B Rev 1.4 (DT)
[ 800.250005] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 800.256959] pc : v3d_job_update_stats+0x60/0x130 [v3d]
[ 800.262112] lr : v3d_job_update_stats+0x48/0x130 [v3d]
[ 800.267251] sp : ffffffc080003e60
[ 800.270555] x29: ffffffc080003e60 x28: ffffffd842784980 x27: 0224012000000000
[ 800.277687] x26: ffffffd84277f630 x25: ffffff81012fd800 x24: 0000000000000020
[ 800.284818] x23: ffffff8040238b08 x22: 0000000000000570 x21: 0000000000000158
[ 800.291948] x20: 0000000000000000 x19: ffffff8040238000 x18: 0000000000000000
[ 800.299078] x17: ffffffa8c1bd2000 x16: ffffffc080000000 x15: 0000000000000000
[ 800.306208] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
[ 800.313338] x11: 0000000000000040 x10: 0000000000001a40 x9 : ffffffd83b39757c
[ 800.320468] x8 : ffffffd842786420 x7 : 7fffffffffffffff x6 : 0000000000ef32b0
[ 800.327598] x5 : 00ffffffffffffff x4 : 0000000000000015 x3 : ffffffd842784980
[ 800.334728] x2 : 0000000000000004 x1 : 0000000000010002 x0 : 000000ba4c0ca382
[ 800.341859] Call trace:
[ 800.344294] v3d_job_update_stats+0x60/0x130 [v3d]
[ 800.349086] v3d_irq+0x124/0x2e0 [v3d]
[ 800.352835] __handle_irq_event_percpu+0x58/0x218
[ 800.357539] handle_irq_event+0x54/0xb8
[ 800.361369] handle_fasteoi_irq+0xac/0x240
[ 800.365458] handle_irq_desc+0x48/0x68
[ 800.369200] generic_handle_domain_irq+0x24/0x38
[ 800.373810] gic_handle_irq+0x48/0xd8
[ 800.377464] call_on_irq_stack+0x24/0x58
[ 800.381379] do_interrupt_handler+0x88/0x98
[ 800.385554] el1_interrupt+0x34/0x68
[ 800.389123] el1h_64_irq_handler+0x18/0x28
[ 800.393211] el1h_64_irq+0x64/0x68
[ 800.396603] default_idle_call+0x3c/0x168
[ 800.400606] do_idle+0x1fc/0x230
[ 800.403827] cpu_startup_entry+0x40/0x50
[ 800.407742] rest_init+0xe4/0xf0
[ 800.410962] start_kernel+0x5e8/0x790
[ 800.414616] __primary_switched+0x80/0x90
[ 800.418622] Code: 8b170277 8b160296 11000421 b9000861 (b9401ac1)
[ 800.424707] ---[ end trace 0000000000000000 ]---
[ 800.457313] ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---
This issue happens when the file descriptor is closed before the jobs
submitted by it are completed. When the job completes, we update the
global GPU stats and the per-fd GPU stats, which are exposed through
fdinfo. If the file descriptor was closed, then the struct `v3d_file_priv`
and its stats were already freed and we can't update the per-fd stats.
Therefore, if the file descriptor was already closed, don't u
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
media: mediatek: vcodec: Can't set dst buffer to done when lat decode error
Core thread will call v4l2_m2m_buf_done to set dst buffer done for
lat architecture. If lat call v4l2_m2m_buf_done_and_job_finish to
free dst buffer when lat decode error, core thread will access kernel
NULL pointer dereference, then crash. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Fix double release compute pasid
If kfd_process_device_init_vm returns failure after vm is converted to
compute vm and vm->pasid set to compute pasid, KFD will not take
pdd->drm_file reference. As a result, drm close file handler maybe
called to release the compute pasid before KFD process destroy worker to
release the same pasid and set vm->pasid to zero, this generates below
WARNING backtrace and NULL pointer access.
Add helper amdgpu_amdkfd_gpuvm_set_vm_pasid and call it at the last step
of kfd_process_device_init_vm, to ensure vm pasid is the original pasid
if acquiring vm failed or is the compute pasid with pdd->drm_file
reference taken to avoid double release same pasid.
amdgpu: Failed to create process VM object
ida_free called for id=32770 which is not allocated.
WARNING: CPU: 57 PID: 72542 at ../lib/idr.c:522 ida_free+0x96/0x140
RIP: 0010:ida_free+0x96/0x140
Call Trace:
amdgpu_pasid_free_delayed+0xe1/0x2a0 [amdgpu]
amdgpu_driver_postclose_kms+0x2d8/0x340 [amdgpu]
drm_file_free.part.13+0x216/0x270 [drm]
drm_close_helper.isra.14+0x60/0x70 [drm]
drm_release+0x6e/0xf0 [drm]
__fput+0xcc/0x280
____fput+0xe/0x20
task_work_run+0x96/0xc0
do_exit+0x3d0/0xc10
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:ida_free+0x76/0x140
Call Trace:
amdgpu_pasid_free_delayed+0xe1/0x2a0 [amdgpu]
amdgpu_driver_postclose_kms+0x2d8/0x340 [amdgpu]
drm_file_free.part.13+0x216/0x270 [drm]
drm_close_helper.isra.14+0x60/0x70 [drm]
drm_release+0x6e/0xf0 [drm]
__fput+0xcc/0x280
____fput+0xe/0x20
task_work_run+0x96/0xc0
do_exit+0x3d0/0xc10 |
| In the Linux kernel, the following vulnerability has been resolved:
cnic: Fix use-after-free bugs in cnic_delete_task
The original code uses cancel_delayed_work() in cnic_cm_stop_bnx2x_hw(),
which does not guarantee that the delayed work item 'delete_task' has
fully completed if it was already running. Additionally, the delayed work
item is cyclic, the flush_workqueue() in cnic_cm_stop_bnx2x_hw() only
blocks and waits for work items that were already queued to the
workqueue prior to its invocation. Any work items submitted after
flush_workqueue() is called are not included in the set of tasks that the
flush operation awaits. This means that after the cyclic work items have
finished executing, a delayed work item may still exist in the workqueue.
This leads to use-after-free scenarios where the cnic_dev is deallocated
by cnic_free_dev(), while delete_task remains active and attempt to
dereference cnic_dev in cnic_delete_task().
A typical race condition is illustrated below:
CPU 0 (cleanup) | CPU 1 (delayed work callback)
cnic_netdev_event() |
cnic_stop_hw() | cnic_delete_task()
cnic_cm_stop_bnx2x_hw() | ...
cancel_delayed_work() | /* the queue_delayed_work()
flush_workqueue() | executes after flush_workqueue()*/
| queue_delayed_work()
cnic_free_dev(dev)//free | cnic_delete_task() //new instance
| dev = cp->dev; //use
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the cyclic delayed work item is properly canceled and that any
ongoing execution of the work item completes before the cnic_dev is
deallocated. Furthermore, since cancel_delayed_work_sync() uses
__flush_work(work, true) to synchronously wait for any currently
executing instance of the work item to finish, the flush_workqueue()
becomes redundant and should be removed.
This bug was identified through static analysis. To reproduce the issue
and validate the fix, I simulated the cnic PCI device in QEMU and
introduced intentional delays — such as inserting calls to ssleep()
within the cnic_delete_task() function — to increase the likelihood
of triggering the bug. |
| In the Linux kernel, the following vulnerability has been resolved:
thermal: intel_powerclamp: Use get_cpu() instead of smp_processor_id() to avoid crash
When CPU 0 is offline and intel_powerclamp is used to inject
idle, it generates kernel BUG:
BUG: using smp_processor_id() in preemptible [00000000] code: bash/15687
caller is debug_smp_processor_id+0x17/0x20
CPU: 4 PID: 15687 Comm: bash Not tainted 5.19.0-rc7+ #57
Call Trace:
<TASK>
dump_stack_lvl+0x49/0x63
dump_stack+0x10/0x16
check_preemption_disabled+0xdd/0xe0
debug_smp_processor_id+0x17/0x20
powerclamp_set_cur_state+0x7f/0xf9 [intel_powerclamp]
...
...
Here CPU 0 is the control CPU by default and changed to the current CPU,
if CPU 0 offlined. This check has to be performed under cpus_read_lock(),
hence the above warning.
Use get_cpu() instead of smp_processor_id() to avoid this BUG.
[ rjw: Subject edits ] |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Fix crash when I/O abort times out
While performing CPU hotplug, a crash with the following stack was seen:
Call Trace:
qla24xx_process_response_queue+0x42a/0x970 [qla2xxx]
qla2x00_start_nvme_mq+0x3a2/0x4b0 [qla2xxx]
qla_nvme_post_cmd+0x166/0x240 [qla2xxx]
nvme_fc_start_fcp_op.part.0+0x119/0x2e0 [nvme_fc]
blk_mq_dispatch_rq_list+0x17b/0x610
__blk_mq_sched_dispatch_requests+0xb0/0x140
blk_mq_sched_dispatch_requests+0x30/0x60
__blk_mq_run_hw_queue+0x35/0x90
__blk_mq_delay_run_hw_queue+0x161/0x180
blk_execute_rq+0xbe/0x160
__nvme_submit_sync_cmd+0x16f/0x220 [nvme_core]
nvmf_connect_admin_queue+0x11a/0x170 [nvme_fabrics]
nvme_fc_create_association.cold+0x50/0x3dc [nvme_fc]
nvme_fc_connect_ctrl_work+0x19/0x30 [nvme_fc]
process_one_work+0x1e8/0x3c0
On abort timeout, completion was called without checking if the I/O was
already completed.
Verify that I/O and abort request are indeed outstanding before attempting
completion. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm: fix use-after-free on probe deferral
The bridge counter was never reset when tearing down the DRM device so
that stale pointers to deallocated structures would be accessed on the
next tear down (e.g. after a second late bind deferral).
Given enough bridges and a few probe deferrals this could currently also
lead to data beyond the bridge array being corrupted.
Patchwork: https://patchwork.freedesktop.org/patch/502665/ |
| In the Linux kernel, the following vulnerability has been resolved:
null_blk: fix poll request timeout handling
When doing io_uring benchmark on /dev/nullb0, it's easy to crash the
kernel if poll requests timeout triggered, as reported by David. [1]
BUG: kernel NULL pointer dereference, address: 0000000000000008
Workqueue: kblockd blk_mq_timeout_work
RIP: 0010:null_timeout_rq+0x4e/0x91
Call Trace:
? null_timeout_rq+0x4e/0x91
blk_mq_handle_expired+0x31/0x4b
bt_iter+0x68/0x84
? bt_tags_iter+0x81/0x81
__sbitmap_for_each_set.constprop.0+0xb0/0xf2
? __blk_mq_complete_request_remote+0xf/0xf
bt_for_each+0x46/0x64
? __blk_mq_complete_request_remote+0xf/0xf
? percpu_ref_get_many+0xc/0x2a
blk_mq_queue_tag_busy_iter+0x14d/0x18e
blk_mq_timeout_work+0x95/0x127
process_one_work+0x185/0x263
worker_thread+0x1b5/0x227
This is indeed a race problem between null_timeout_rq() and null_poll().
null_poll() null_timeout_rq()
spin_lock(&nq->poll_lock)
list_splice_init(&nq->poll_list, &list)
spin_unlock(&nq->poll_lock)
while (!list_empty(&list))
req = list_first_entry()
list_del_init()
...
blk_mq_add_to_batch()
// req->rq_next = NULL
spin_lock(&nq->poll_lock)
// rq->queuelist->next == NULL
list_del_init(&rq->queuelist)
spin_unlock(&nq->poll_lock)
Fix these problems by setting requests state to MQ_RQ_COMPLETE under
nq->poll_lock protection, in which null_timeout_rq() can safely detect
this race and early return.
Note this patch just fix the kernel panic when request timeout happen.
[1] https://lore.kernel.org/all/3893581.1691785261@warthog.procyon.org.uk/ |
| In the Linux kernel, the following vulnerability has been resolved:
zram: fix slot write race condition
Parallel concurrent writes to the same zram index result in leaked
zsmalloc handles. Schematically we can have something like this:
CPU0 CPU1
zram_slot_lock()
zs_free(handle)
zram_slot_lock()
zram_slot_lock()
zs_free(handle)
zram_slot_lock()
compress compress
handle = zs_malloc() handle = zs_malloc()
zram_slot_lock
zram_set_handle(handle)
zram_slot_lock
zram_slot_lock
zram_set_handle(handle)
zram_slot_lock
Either CPU0 or CPU1 zsmalloc handle will leak because zs_free() is done
too early. In fact, we need to reset zram entry right before we set its
new handle, all under the same slot lock scope. |
| In the Linux kernel, the following vulnerability has been resolved:
dm-stripe: fix a possible integer overflow
There's a possible integer overflow in stripe_io_hints if we have too
large chunk size. Test if the overflow happened, and if it did, don't set
limits->io_min and limits->io_opt; |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: qcom: q6apm-lpass-dais: Fix NULL pointer dereference if source graph failed
If earlier opening of source graph fails (e.g. ADSP rejects due to
incorrect audioreach topology), the graph is closed and
"dai_data->graph[dai->id]" is assigned NULL. Preparing the DAI for sink
graph continues though and next call to q6apm_lpass_dai_prepare()
receives dai_data->graph[dai->id]=NULL leading to NULL pointer
exception:
qcom-apm gprsvc:service:2:1: Error (1) Processing 0x01001002 cmd
qcom-apm gprsvc:service:2:1: DSP returned error[1001002] 1
q6apm-lpass-dais 30000000.remoteproc:glink-edge:gpr:service@1:bedais: fail to start APM port 78
q6apm-lpass-dais 30000000.remoteproc:glink-edge:gpr:service@1:bedais: ASoC: error at snd_soc_pcm_dai_prepare on TX_CODEC_DMA_TX_3: -22
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a8
...
Call trace:
q6apm_graph_media_format_pcm+0x48/0x120 (P)
q6apm_lpass_dai_prepare+0x110/0x1b4
snd_soc_pcm_dai_prepare+0x74/0x108
__soc_pcm_prepare+0x44/0x160
dpcm_be_dai_prepare+0x124/0x1c0 |
| In the Linux kernel, the following vulnerability has been resolved:
drm: bridge: anx7625: Fix NULL pointer dereference with early IRQ
If the interrupt occurs before resource initialization is complete, the
interrupt handler/worker may access uninitialized data such as the I2C
tcpc_client device, potentially leading to NULL pointer dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: core: Check for rtd == NULL in snd_soc_remove_pcm_runtime()
snd_soc_remove_pcm_runtime() might be called with rtd == NULL which will
leads to null pointer dereference.
This was reproduced with topology loading and marking a link as ignore
due to missing hardware component on the system.
On module removal the soc_tplg_remove_link() would call
snd_soc_remove_pcm_runtime() with rtd == NULL since the link was ignored,
no runtime was created. |
| In the Linux kernel, the following vulnerability has been resolved:
fbdev: fix potential buffer overflow in do_register_framebuffer()
The current implementation may lead to buffer overflow when:
1. Unregistration creates NULL gaps in registered_fb[]
2. All array slots become occupied despite num_registered_fb < FB_MAX
3. The registration loop exceeds array bounds
Add boundary check to prevent registered_fb[FB_MAX] access. |
| In the Linux kernel, the following vulnerability has been resolved:
net: enetc: avoid buffer leaks on xdp_do_redirect() failure
Before enetc_clean_rx_ring_xdp() calls xdp_do_redirect(), each software
BD in the RX ring between index orig_i and i can have one of 2 refcount
values on its page.
We are the owner of the current buffer that is being processed, so the
refcount will be at least 1.
If the current owner of the buffer at the diametrically opposed index
in the RX ring (i.o.w, the other half of this page) has not yet called
kfree(), this page's refcount could even be 2.
enetc_page_reusable() in enetc_flip_rx_buff() tests for the page
refcount against 1, and [ if it's 2 ] does not attempt to reuse it.
But if enetc_flip_rx_buff() is put after the xdp_do_redirect() call,
the page refcount can have one of 3 values. It can also be 0, if there
is no owner of the other page half, and xdp_do_redirect() for this
buffer ran so far that it triggered a flush of the devmap/cpumap bulk
queue, and the consumers of those bulk queues also freed the buffer,
all by the time xdp_do_redirect() returns the execution back to enetc.
This is the reason why enetc_flip_rx_buff() is called before
xdp_do_redirect(), but there is a big flaw with that reasoning:
enetc_flip_rx_buff() will set rx_swbd->page = NULL on both sides of the
enetc_page_reusable() branch, and if xdp_do_redirect() returns an error,
we call enetc_xdp_free(), which does not deal gracefully with that.
In fact, what happens is quite special. The page refcounts start as 1.
enetc_flip_rx_buff() figures they're reusable, transfers these
rx_swbd->page pointers to a different rx_swbd in enetc_reuse_page(), and
bumps the refcount to 2. When xdp_do_redirect() later returns an error,
we call the no-op enetc_xdp_free(), but we still haven't lost the
reference to that page. A copy of it is still at rx_ring->next_to_alloc,
but that has refcount 2 (and there are no concurrent owners of it in
flight, to drop the refcount). What really kills the system is when
we'll flip the rx_swbd->page the second time around. With an updated
refcount of 2, the page will not be reusable and we'll really leak it.
Then enetc_new_page() will have to allocate more pages, which will then
eventually leak again on further errors from xdp_do_redirect().
The problem, summarized, is that we zeroize rx_swbd->page before we're
completely done with it, and this makes it impossible for the error path
to do something with it.
Since the packet is potentially multi-buffer and therefore the
rx_swbd->page is potentially an array, manual passing of the old
pointers between enetc_flip_rx_buff() and enetc_xdp_free() is a bit
difficult.
For the sake of going with a simple solution, we accept the possibility
of racing with xdp_do_redirect(), and we move the flip procedure to
execute only on the redirect success path. By racing, I mean that the
page may be deemed as not reusable by enetc (having a refcount of 0),
but there will be no leak in that case, either.
Once we accept that, we have something better to do with buffers on
XDP_REDIRECT failure. Since we haven't performed half-page flipping yet,
we won't, either (and this way, we can avoid enetc_xdp_free()
completely, which gives the entire page to the slab allocator).
Instead, we'll call enetc_xdp_drop(), which will recycle this half of
the buffer back to the RX ring. |
