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| author | Zheyu Ma <zheyuma97@gmail.com> | 2022-08-30 15:34:50 +0800 |
|---|---|---|
| committer | Robert Foss <robert.foss@linaro.org> | 2022-08-30 10:09:23 +0200 |
| commit | 1ff673333d46d2c1b053ebd0c1c7c7c79e36943e (patch) | |
| tree | d1096a1fa81fa17a3dd358ec38594a60cfde96e1 /drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | |
| parent | 5b04aab6d49578eacd6d341e281c70a769f96126 (diff) | |
| download | linux-1ff673333d46d2c1b053ebd0c1c7c7c79e36943e.tar.bz2 | |
drm/bridge: megachips: Fix a null pointer dereference bug
When removing the module we will get the following warning:
[ 31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered
[ 31.912484] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
[ 31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
[ 31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130
[ 31.921825] Call Trace:
[ 31.922533] stdp4028_ge_b850v3_fw_remove+0x34/0x60 [megachips_stdpxxxx_ge_b850v3_fw]
[ 31.923139] i2c_device_remove+0x181/0x1f0
The two bridges (stdp2690, stdp4028) do not probe at the same time, so
the driver does not call ge_b850v3_resgiter() when probing, causing the
driver to try to remove the object that has not been initialized.
Fix this by checking whether both the bridges are probed.
Fixes: 11632d4aa2b3 ("drm/bridge: megachips: Ensure both bridges are probed before registration")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220830073450.1897020-1-zheyuma97@gmail.com
Diffstat (limited to 'drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c')
| -rw-r--r-- | drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c index cce98bf2a4e7..72248a565579 100644 --- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c @@ -296,7 +296,9 @@ static void ge_b850v3_lvds_remove(void) * This check is to avoid both the drivers * removing the bridge in their remove() function */ - if (!ge_b850v3_lvds_ptr) + if (!ge_b850v3_lvds_ptr || + !ge_b850v3_lvds_ptr->stdp2690_i2c || + !ge_b850v3_lvds_ptr->stdp4028_i2c) goto out; drm_bridge_remove(&ge_b850v3_lvds_ptr->bridge); |