[ Upstream commit ba18dad0fb ]
platform_get_irq() returns negative error number instead 0 on failure.
And the doc of platform_get_irq() provides a usage example:
int irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
Fix the check of return value to catch errors correctly.
Fixes: f7a388d6cd ("power: reset: Add a driver for the Gemini poweroff")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bc97f9c6f9 ]
{__,}napi_alloc_skb() allocates and reserves additional NET_SKB_PAD
+ NET_IP_ALIGN for any skb.
OTOH, i40e_construct_skb_zc() currently allocates and reserves
additional `xdp->data - xdp->data_hard_start`, which is
XDP_PACKET_HEADROOM for XSK frames.
There's no need for that at all as the frame is post-XDP and will
go only to the networking stack core.
Pass the size of the actual data only to __napi_alloc_skb() and
don't reserve anything. This will give enough headroom for stack
processing.
Fixes: 0a714186d3 ("i40e: add AF_XDP zero-copy Rx support")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d1e0df1c57 ]
Syzbot reported 2 KMSAN bugs in ath9k. All of them are caused by missing
field initialization.
In htc_connect_service() svc_meta_len and pad are not initialized. Based
on code it looks like in current skb there is no service data, so simply
initialize svc_meta_len to 0.
htc_issue_send() does not initialize htc_frame_hdr::control array. Based
on firmware code, it will initialize it by itself, so simply zero whole
array to make KMSAN happy
Fail logs:
BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
hif_usb_send_regout drivers/net/wireless/ath/ath9k/hif_usb.c:127 [inline]
hif_usb_send+0x5f0/0x16f0 drivers/net/wireless/ath/ath9k/hif_usb.c:479
htc_issue_send drivers/net/wireless/ath/ath9k/htc_hst.c:34 [inline]
htc_connect_service+0x143e/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:275
...
Uninit was created at:
slab_post_alloc_hook mm/slab.h:524 [inline]
slab_alloc_node mm/slub.c:3251 [inline]
__kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4974
kmalloc_reserve net/core/skbuff.c:354 [inline]
__alloc_skb+0x545/0xf90 net/core/skbuff.c:426
alloc_skb include/linux/skbuff.h:1126 [inline]
htc_connect_service+0x1029/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:258
...
Bytes 4-7 of 18 are uninitialized
Memory access of size 18 starts at ffff888027377e00
BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
hif_usb_send_regout drivers/net/wireless/ath/ath9k/hif_usb.c:127 [inline]
hif_usb_send+0x5f0/0x16f0 drivers/net/wireless/ath/ath9k/hif_usb.c:479
htc_issue_send drivers/net/wireless/ath/ath9k/htc_hst.c:34 [inline]
htc_connect_service+0x143e/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:275
...
Uninit was created at:
slab_post_alloc_hook mm/slab.h:524 [inline]
slab_alloc_node mm/slub.c:3251 [inline]
__kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4974
kmalloc_reserve net/core/skbuff.c:354 [inline]
__alloc_skb+0x545/0xf90 net/core/skbuff.c:426
alloc_skb include/linux/skbuff.h:1126 [inline]
htc_connect_service+0x1029/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:258
...
Bytes 16-17 of 18 are uninitialized
Memory access of size 18 starts at ffff888027377e00
Fixes: fb9987d0f7 ("ath9k_htc: Support for AR9271 chipset.")
Reported-by: syzbot+f83a1df1ed4f67e8d8ad@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220115122733.11160-1-paskripkin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 588a70177d ]
In amdgpu_dm_connector_add_common_modes(), amdgpu_dm_create_common_mode()
is assigned to mode and is passed to drm_mode_probed_add() directly after
that. drm_mode_probed_add() passes &mode->head to list_add_tail(), and
there is a dereference of it in list_add_tail() without recoveries, which
could lead to NULL pointer dereference on failure of
amdgpu_dm_create_common_mode().
Fix this by adding a NULL check of mode.
This bug was found by a static analyzer.
Builds with 'make allyesconfig' show no new warnings,
and our static analyzer no longer warns about this code.
Fixes: e7b07ceef2 ("drm/amd/display: Merge amdgpu_dm_types and amdgpu_dm")
Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 75478b3b39 ]
The current code, when parsing the EDID Deep Color depths, that the
YUV422 cannot be used, referring to the HDMI 1.3 Specification.
This specification, in its section 6.2.4, indeed states:
For each supported Deep Color mode, RGB 4:4:4 shall be supported and
optionally YCBCR 4:4:4 may be supported.
YCBCR 4:2:2 is not permitted for any Deep Color mode.
This indeed can be interpreted like the code does, but the HDMI 1.4
specification further clarifies that statement in its section 6.2.4:
For each supported Deep Color mode, RGB 4:4:4 shall be supported and
optionally YCBCR 4:4:4 may be supported.
YCBCR 4:2:2 is also 36-bit mode but does not require the further use
of the Deep Color modes described in section 6.5.2 and 6.5.3.
This means that, even though YUV422 can be used with 12 bit per color,
it shouldn't be treated as a deep color mode.
This is also broken with YUV444 if it's supported by the display, but
DRM_EDID_HDMI_DC_Y444 isn't set. In such a case, the code will clear
color_formats of the YUV444 support set previously in
drm_parse_cea_ext(), but will not set it back.
Since the formats supported are already setup properly in
drm_parse_cea_ext(), let's just remove the code modifying the formats in
drm_parse_hdmi_deep_color_info()
Fixes: d0c94692e0 ("drm/edid: Parse and handle HDMI deep color modes.")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220120151625.594595-3-maxime@cerno.tech
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3e68f331c8 ]
For the possible failure of the platform_get_irq(), the returned irq
could be error number and will finally cause the failure of the
request_irq().
Consider that platform_get_irq() can now in certain cases return
-EPROBE_DEFER, and the consequences of letting request_irq() effectively
convert that into -EINVAL, even at probe time rather than later on.
So it might be better to check just now.
Fixes: 2c22120fbd ("MTD: OneNAND: interrupt based wait support")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220104162658.1988142-1-jiasheng@iscas.ac.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9d7cbe2b9c ]
kvartet reported, that hci_uart_tx_wakeup() uses uninitialized rwsem.
The problem was in wrong place for percpu_init_rwsem() call.
hci_uart_proto::open() may register a timer whose callback may call
hci_uart_tx_wakeup(). There is a chance, that hci_uart_register_device()
thread won't be fast enough to call percpu_init_rwsem().
Fix it my moving percpu_init_rwsem() call before p->open().
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 2 PID: 18524 Comm: syz-executor.5 Not tainted 5.16.0-rc6 #9
...
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
assign_lock_key kernel/locking/lockdep.c:951 [inline]
register_lock_class+0x148d/0x1950 kernel/locking/lockdep.c:1263
__lock_acquire+0x106/0x57e0 kernel/locking/lockdep.c:4906
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5602
percpu_down_read_trylock include/linux/percpu-rwsem.h:92 [inline]
hci_uart_tx_wakeup+0x12e/0x490 drivers/bluetooth/hci_ldisc.c:124
h5_timed_event+0x32f/0x6a0 drivers/bluetooth/hci_h5.c:188
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
Fixes: d73e172816 ("Bluetooth: hci_serdev: Init hci_uart proto_lock to avoid oops")
Reported-by: Yiru Xu <xyru1999@gmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e3fb3d4418 ]
In function ath10k_wow_convert_8023_to_80211(), it will do memcpy for
the new->pattern, and currently the new->pattern and new->mask is same
with the old, then the memcpy of new->pattern will also overwrite the
old->pattern, because the header format of new->pattern is 802.11,
its length is larger than the old->pattern which is 802.3. Then the
operation of "Copy frame body" will copy a mistake value because the
body memory has been overwrite when memcpy the new->pattern.
Assign another empty value to new_pattern to avoid the overwrite issue.
Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00049
Fixes: fa3440fa2f ("ath10k: convert wow pattern from 802.3 to 802.11")
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20211222031347.25463-1-quic_wgong@quicinc.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6ae0a4d8fe ]
This function only calls of_node_put() in the regular path.
And it will cause refcount leak in error paths.
For example, when codec_np is NULL, saif_np[0] and saif_np[1]
are not NULL, it will cause leaks.
of_node_put() will check if the node pointer is NULL, so we can
call it directly to release the refcount of regular pointers.
Fixes: e968194b45 ("ASoC: mxs: add device tree support for mxs-sgtl5000")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220308020146.26496-1-linmq006@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 25e9413921 ]
The VIDIOC_G_FBUF and related overlay ioctls no longer worked (-ENOTTY was
returned).
The root cause was the introduction of the caps field in ivtv-driver.h.
While loading the ivtvfb module would update the video_device device_caps
field with V4L2_CAP_VIDEO_OUTPUT_OVERLAY it would not update that caps
field, and that's what the overlay ioctls would look at.
It's a bad idea to keep information in two places, so drop the caps field
and only use vdev.device_caps.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reported-by: Martin Dauskardt <martin.dauskardt@gmx.de>
Fixes: 2161536516 (media: media/pci: set device_caps in struct video_device)
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a58c22cfbb ]
The device_node pointer is returned by of_parse_phandle() with refcount
incremented. We should use of_node_put() on it when done.
Fixes: f76ee892a9 ("omapfb: copy omapdss & displays for omapfb")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bf0cd60b7e ]
AV/C deferred transaction was supported at a commit 00a7bb81c2 ("ALSA:
firewire-lib: Add support for deferred transaction") while 'deferrable'
flag can be uninitialized for non-control/notify AV/C transactions.
UBSAN reports it:
kernel: ================================================================================
kernel: UBSAN: invalid-load in /build/linux-aa0B4d/linux-5.15.0/sound/firewire/fcp.c:363:9
kernel: load of value 158 is not a valid value for type '_Bool'
kernel: CPU: 3 PID: 182227 Comm: irq/35-firewire Tainted: P OE 5.15.0-18-generic #18-Ubuntu
kernel: Hardware name: Gigabyte Technology Co., Ltd. AX370-Gaming 5/AX370-Gaming 5, BIOS F42b 08/01/2019
kernel: Call Trace:
kernel: <IRQ>
kernel: show_stack+0x52/0x58
kernel: dump_stack_lvl+0x4a/0x5f
kernel: dump_stack+0x10/0x12
kernel: ubsan_epilogue+0x9/0x45
kernel: __ubsan_handle_load_invalid_value.cold+0x44/0x49
kernel: fcp_response.part.0.cold+0x1a/0x2b [snd_firewire_lib]
kernel: fcp_response+0x28/0x30 [snd_firewire_lib]
kernel: fw_core_handle_request+0x230/0x3d0 [firewire_core]
kernel: handle_ar_packet+0x1d9/0x200 [firewire_ohci]
kernel: ? handle_ar_packet+0x1d9/0x200 [firewire_ohci]
kernel: ? transmit_complete_callback+0x9f/0x120 [firewire_core]
kernel: ar_context_tasklet+0xa8/0x2e0 [firewire_ohci]
kernel: tasklet_action_common.constprop.0+0xea/0xf0
kernel: tasklet_action+0x22/0x30
kernel: __do_softirq+0xd9/0x2e3
kernel: ? irq_finalize_oneshot.part.0+0xf0/0xf0
kernel: do_softirq+0x75/0xa0
kernel: </IRQ>
kernel: <TASK>
kernel: __local_bh_enable_ip+0x50/0x60
kernel: irq_forced_thread_fn+0x7e/0x90
kernel: irq_thread+0xba/0x190
kernel: ? irq_thread_fn+0x60/0x60
kernel: kthread+0x11e/0x140
kernel: ? irq_thread_check_affinity+0xf0/0xf0
kernel: ? set_kthread_struct+0x50/0x50
kernel: ret_from_fork+0x22/0x30
kernel: </TASK>
kernel: ================================================================================
This commit fixes the bug. The bug has no disadvantage for the non-
control/notify AV/C transactions since the flag has an effect for AV/C
response with INTERIM (0x0f) status which is not used for the transactions
in AV/C general specification.
Fixes: 00a7bb81c2 ("ALSA: firewire-lib: Add support for deferred transaction")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20220304125647.78430-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit de2c6f9881 ]
There is one call trace that snd_soc_register_card()
->snd_soc_bind_card()->soc_init_pcm_runtime()
->snd_soc_dai_compress_new()->snd_soc_new_compress().
In the trace the 'codec_dai' transfers from card->dai_link,
and we can see from the snd_soc_add_pcm_runtime() in
snd_soc_bind_card() that, if value of card->dai_link->num_codecs
is 0, then 'codec_dai' could be null pointer caused
by index out of bound in 'asoc_rtd_to_codec(rtd, 0)'.
And snd_soc_register_card() is called by various platforms.
Therefore, it is better to add the check in the case of misusing.
And because 'cpu_dai' has already checked in soc_init_pcm_runtime(),
there is no need to check again.
Adding the check as follow, then if 'codec_dai' is null,
snd_soc_new_compress() will not pass through the check
'if (playback + capture != 1)', avoiding the leftover use of
'codec_dai'.
Fixes: 467fece ("ASoC: soc-dai: move snd_soc_dai_stream_valid() to soc-dai.c")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/1634285633-529368-1-git-send-email-jiasheng@iscas.ac.cn
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 55927cb44d ]
After converting ahci-platform txt binding to yaml nodename is reported
as not matching the standard:
arch/arm64/boot/dts/broadcom/northstar2/ns2-svk.dt.yaml:
ahci@663f2000: $nodename:0: 'ahci@663f2000' does not match '^sata(@.*)?$'
Fix it to match binding.
Fixes: ac9aae00f0 ("arm64: dts: Add SATA3 AHCI and SATA3 PHY DT nodes for NS2")
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c953c764e5 ]
Broadcom ns2 platform has spi-cpol and spi-cpho properties set
incorrectly. As per spi-slave-peripheral-prop.yaml, these properties are
of flag or boolean type and not integer type. Fix the values.
Fixes: d69dbd9f41 (arm64: dts: Add ARM PL022 SPI DT nodes for NS2)
Signed-off-by: Kuldeep Singh <singh.kuldeep87k@gmail.com>
CC: Ray Jui <rjui@broadcom.com>
CC: Scott Branden <sbranden@broadcom.com>
CC: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a97b693c37 ]
These two architectures implement 8-byte get_user() through
a memcpy() into a four-byte variable, which won't fit.
Use a temporary 64-bit variable instead here, and use a double
cast the way that risc-v and openrisc do to avoid compile-time
warnings.
Fixes: 6a090e9797 ("arch/microblaze: support get_user() of size 8 bytes")
Fixes: 5ccc6af5e8 ("nios2: Memory management")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c08eadca1b ]
The commit 47677e51e2a4("[media] em28xx: Only deallocate struct
em28xx after finishing all extensions") adds kref_get to many init
functions (e.g., em28xx_audio_init). However, kref_init is called too
late in em28xx_usb_probe, since em28xx_init_dev before will invoke
those init functions and call kref_get function. Then refcount bug
occurs in my local syzkaller instance.
Fix it by moving kref_init before em28xx_init_dev. This issue occurs
not only in dev but also dev->dev_next.
Fixes: 47677e51e2 ("[media] em28xx: Only deallocate struct em28xx after finishing all extensions")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4a92fc6e55 ]
Calling hdmi_infoframe_unpack() with static sizeof(buffer) skips all
the size checking done later in hdmi_infoframe_unpack(). A better
value is the amount of data read into buffer.
Fixes: 480b8b3e42 ("video/hdmi: Pass buffer size to infoframe unpack functions")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c3d66a164c ]
platform_get_irq() returns negative error number instead 0 on failure.
And the doc of platform_get_irq() provides a usage example:
int irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
Fix the check of return value to catch errors correctly.
Fixes: cdd5de500b ("soc: ti: Add wkup_m3_ipc driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Dave Gerlach <d-gerlach@ti.com>
Link: https://lore.kernel.org/r/20220114062840.16620-1-linmq006@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8030cb9a55 ]
Quoting the header comments, IRQF_ONESHOT is "Used by threaded interrupts
which need to keep the irq line disabled until the threaded handler has
been run.". When applied to an interrupt that doesn't request a threaded
irq then IRQF_ONESHOT has a lesser known (undocumented?) side effect,
which it to disable the forced threading of the irq. For "normal" kernels
(without forced threading) then, if there is no thread_fn, then
IRQF_ONESHOT is a nop.
In this case disabling forced threading is not appropriate for this driver
because it calls wake_up_all() and this API cannot be called from
no-thread interrupt handlers on PREEMPT_RT systems (deadlock risk, triggers
sleeping-while-atomic warnings).
Fix this by removing IRQF_ONESHOT.
Fixes: 2209481409 ("soc: qcom: Add AOSS QMP driver")
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
[bjorn: Added Fixes tag]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220127173554.158111-1-daniel.thompson@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5a811126d3 ]
Because of the possible failure of the allocation, data->domains might
be NULL pointer and will cause the dereference of the NULL pointer
later.
Therefore, it might be better to check it and directly return -ENOMEM
without releasing data manually if fails, because the comment of the
devm_kmalloc() says "Memory allocated with this function is
automatically freed on driver detach.".
Fixes: bbe3a66c3f ("soc: qcom: rpmpd: Add a Power domain driver to model corners")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211231094419.1941054-1-jiasheng@iscas.ac.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 78482af095 ]
This code has two bugs:
1) "cnt" is 255 but the size of the buffer is 256 so the last byte is
not used.
2) If we try to print more than 255 characters then "cnt" will be
negative and that will trigger a WARN() in snprintf(). The fix for
this is to use scnprintf() instead of snprintf().
We can re-write this code to be cleaner:
1) Rename "offset" to "off" because that's shorter.
2) Get rid of the "cnt" variable and just use "size - off" directly.
3) Get rid of the "read" variable and just increment "off" directly.
Fixes: 96fe6a2109 ("fbdev: Add VESA Coordinated Video Timings (CVT) support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
