| Message ID | 20241206135507.1274357-1-guoqing.jiang@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/mediatek: Set private->all_drm_private[i]->drm to NULL if mtk_drm_bind returns err | expand |
Hi, Guoqing: On Fri, 2024-12-06 at 21:55 +0800, Guoqing Jiang wrote: > External email : Please do not click links or open attachments until you have verified the sender or the content. > > > The pointer need to be set to NULL, otherwise KASAN complains about > use-after-free. Because in mtk_drm_bind, all private's drm are set > as follows. > > private->all_drm_private[i]->drm = drm; > > And drm will be released by drm_dev_put in case mtk_drm_kms_init returns > failure. However, the shutdown path still accesses the previous allocated > memory in drm_atomic_helper_shutdown. > > [ 84.874820] watchdog: watchdog0: watchdog did not stop! > [ 86.512054] ================================================================== > [ 86.513162] BUG: KASAN: use-after-free in drm_atomic_helper_shutdown+0x33c/0x378 > [ 86.514258] Read of size 8 at addr ffff0000d46fc068 by task shutdown/1 > [ 86.515213] > [ 86.515455] CPU: 1 UID: 0 PID: 1 Comm: shutdown Not tainted 6.13.0-rc1-mtk+gfa1a78e5d24b-dirty #55 > [ 86.516752] Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2022.10 10/01/2022 > [ 86.517960] Call trace: > [ 86.518333] show_stack+0x20/0x38 (C) > [ 86.518891] dump_stack_lvl+0x90/0xd0 > [ 86.519443] print_report+0xf8/0x5b0 > [ 86.519985] kasan_report+0xb4/0x100 > [ 86.520526] __asan_report_load8_noabort+0x20/0x30 > [ 86.521240] drm_atomic_helper_shutdown+0x33c/0x378 > [ 86.521966] mtk_drm_shutdown+0x54/0x80 > [ 86.522546] platform_shutdown+0x64/0x90 > [ 86.523137] device_shutdown+0x260/0x5b8 > [ 86.523728] kernel_restart+0x78/0xf0 > [ 86.524282] __do_sys_reboot+0x258/0x2f0 > [ 86.524871] __arm64_sys_reboot+0x90/0xd8 > [ 86.525473] invoke_syscall+0x74/0x268 > [ 86.526041] el0_svc_common.constprop.0+0xb0/0x240 > [ 86.526751] do_el0_svc+0x4c/0x70 > [ 86.527251] el0_svc+0x4c/0xc0 > [ 86.527719] el0t_64_sync_handler+0x144/0x168 > [ 86.528367] el0t_64_sync+0x198/0x1a0 > [ 86.528920] > [ 86.529157] The buggy address belongs to the physical page: > [ 86.529972] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff0000d46fd4d0 pfn:0x1146fc > [ 86.531319] flags: 0xbfffc0000000000(node=0|zone=2|lastcpupid=0xffff) > [ 86.532267] raw: 0bfffc0000000000 0000000000000000 dead000000000122 0000000000000000 > [ 86.533390] raw: ffff0000d46fd4d0 0000000000000000 00000000ffffffff 0000000000000000 > [ 86.534511] page dumped because: kasan: bad access detected > [ 86.535323] > [ 86.535559] Memory state around the buggy address: > [ 86.536265] ffff0000d46fbf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > [ 86.537314] ffff0000d46fbf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > [ 86.538363] >ffff0000d46fc000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > [ 86.544733] ^ > [ 86.551057] ffff0000d46fc080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > [ 86.557510] ffff0000d46fc100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > [ 86.563928] ================================================================== > [ 86.571093] Disabling lock debugging due to kernel taint > [ 86.577642] Unable to handle kernel paging request at virtual address e0e9c0920000000b > [ 86.581834] KASAN: maybe wild-memory-access in range [0x0752049000000058-0x075204900000005f] > ... Refer to [1] to add Fixes tag. [1] https://www.kernel.org/doc/html/v6.12/process/submitting-patches.html Regards, CK > > Signed-off-by: Guoqing Jiang <guoqing.jiang@canonical.com> > --- > drivers/gpu/drm/mediatek/mtk_drm_drv.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > index 9a8ef8558da9..0062374f75d5 100644 > --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c > +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > @@ -673,6 +673,8 @@ static int mtk_drm_bind(struct device *dev) > err_free: > private->drm = NULL; > drm_dev_put(drm); > + for (i = 0; i < private->data->mmsys_dev_num; i++) > + private->all_drm_private[i]->drm = NULL; > return ret; > } > > -- > 2.35.3 > >
Hi, On 12/10/24 17:16, CK Hu (胡俊光) wrote: > Hi, Guoqing: > > On Fri, 2024-12-06 at 21:55 +0800, Guoqing Jiang wrote: >> External email : Please do not click links or open attachments until you have verified the sender or the content. >> >> >> The pointer need to be set to NULL, otherwise KASAN complains about >> use-after-free. Because in mtk_drm_bind, all private's drm are set >> as follows. >> >> private->all_drm_private[i]->drm = drm; >> >> And drm will be released by drm_dev_put in case mtk_drm_kms_init returns >> failure. However, the shutdown path still accesses the previous allocated >> memory in drm_atomic_helper_shutdown. >> >> [ 84.874820] watchdog: watchdog0: watchdog did not stop! >> [ 86.512054] ================================================================== >> [ 86.513162] BUG: KASAN: use-after-free in drm_atomic_helper_shutdown+0x33c/0x378 >> [ 86.514258] Read of size 8 at addr ffff0000d46fc068 by task shutdown/1 >> [ 86.515213] >> [ 86.515455] CPU: 1 UID: 0 PID: 1 Comm: shutdown Not tainted 6.13.0-rc1-mtk+gfa1a78e5d24b-dirty #55 >> [ 86.516752] Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2022.10 10/01/2022 >> [ 86.517960] Call trace: >> [ 86.518333] show_stack+0x20/0x38 (C) >> [ 86.518891] dump_stack_lvl+0x90/0xd0 >> [ 86.519443] print_report+0xf8/0x5b0 >> [ 86.519985] kasan_report+0xb4/0x100 >> [ 86.520526] __asan_report_load8_noabort+0x20/0x30 >> [ 86.521240] drm_atomic_helper_shutdown+0x33c/0x378 >> [ 86.521966] mtk_drm_shutdown+0x54/0x80 >> [ 86.522546] platform_shutdown+0x64/0x90 >> [ 86.523137] device_shutdown+0x260/0x5b8 >> [ 86.523728] kernel_restart+0x78/0xf0 >> [ 86.524282] __do_sys_reboot+0x258/0x2f0 >> [ 86.524871] __arm64_sys_reboot+0x90/0xd8 >> [ 86.525473] invoke_syscall+0x74/0x268 >> [ 86.526041] el0_svc_common.constprop.0+0xb0/0x240 >> [ 86.526751] do_el0_svc+0x4c/0x70 >> [ 86.527251] el0_svc+0x4c/0xc0 >> [ 86.527719] el0t_64_sync_handler+0x144/0x168 >> [ 86.528367] el0t_64_sync+0x198/0x1a0 >> [ 86.528920] >> [ 86.529157] The buggy address belongs to the physical page: >> [ 86.529972] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff0000d46fd4d0 pfn:0x1146fc >> [ 86.531319] flags: 0xbfffc0000000000(node=0|zone=2|lastcpupid=0xffff) >> [ 86.532267] raw: 0bfffc0000000000 0000000000000000 dead000000000122 0000000000000000 >> [ 86.533390] raw: ffff0000d46fd4d0 0000000000000000 00000000ffffffff 0000000000000000 >> [ 86.534511] page dumped because: kasan: bad access detected >> [ 86.535323] >> [ 86.535559] Memory state around the buggy address: >> [ 86.536265] ffff0000d46fbf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >> [ 86.537314] ffff0000d46fbf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >> [ 86.538363] >ffff0000d46fc000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >> [ 86.544733] ^ >> [ 86.551057] ffff0000d46fc080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >> [ 86.557510] ffff0000d46fc100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >> [ 86.563928] ================================================================== >> [ 86.571093] Disabling lock debugging due to kernel taint >> [ 86.577642] Unable to handle kernel paging request at virtual address e0e9c0920000000b >> [ 86.581834] KASAN: maybe wild-memory-access in range [0x0752049000000058-0x075204900000005f] >> ... > Refer to [1] to add Fixes tag. > > [1] https://www.kernel.org/doc/html/v6.12/process/submitting-patches.html Thanks for reminder! I think the problem is caused by commit 1ef7ed48356c, so Fixes: 1ef7ed48356c ("drm/mediatek: Modify mediatek-drm for mt8195 multi mmsys support") And before send a new version with the tag, I will wait a few days for other comments. Thanks, Guoqing
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index 9a8ef8558da9..0062374f75d5 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -673,6 +673,8 @@ static int mtk_drm_bind(struct device *dev) err_free: private->drm = NULL; drm_dev_put(drm); + for (i = 0; i < private->data->mmsys_dev_num; i++) + private->all_drm_private[i]->drm = NULL; return ret; }
The pointer need to be set to NULL, otherwise KASAN complains about use-after-free. Because in mtk_drm_bind, all private's drm are set as follows. private->all_drm_private[i]->drm = drm; And drm will be released by drm_dev_put in case mtk_drm_kms_init returns failure. However, the shutdown path still accesses the previous allocated memory in drm_atomic_helper_shutdown. [ 84.874820] watchdog: watchdog0: watchdog did not stop! [ 86.512054] ================================================================== [ 86.513162] BUG: KASAN: use-after-free in drm_atomic_helper_shutdown+0x33c/0x378 [ 86.514258] Read of size 8 at addr ffff0000d46fc068 by task shutdown/1 [ 86.515213] [ 86.515455] CPU: 1 UID: 0 PID: 1 Comm: shutdown Not tainted 6.13.0-rc1-mtk+gfa1a78e5d24b-dirty #55 [ 86.516752] Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2022.10 10/01/2022 [ 86.517960] Call trace: [ 86.518333] show_stack+0x20/0x38 (C) [ 86.518891] dump_stack_lvl+0x90/0xd0 [ 86.519443] print_report+0xf8/0x5b0 [ 86.519985] kasan_report+0xb4/0x100 [ 86.520526] __asan_report_load8_noabort+0x20/0x30 [ 86.521240] drm_atomic_helper_shutdown+0x33c/0x378 [ 86.521966] mtk_drm_shutdown+0x54/0x80 [ 86.522546] platform_shutdown+0x64/0x90 [ 86.523137] device_shutdown+0x260/0x5b8 [ 86.523728] kernel_restart+0x78/0xf0 [ 86.524282] __do_sys_reboot+0x258/0x2f0 [ 86.524871] __arm64_sys_reboot+0x90/0xd8 [ 86.525473] invoke_syscall+0x74/0x268 [ 86.526041] el0_svc_common.constprop.0+0xb0/0x240 [ 86.526751] do_el0_svc+0x4c/0x70 [ 86.527251] el0_svc+0x4c/0xc0 [ 86.527719] el0t_64_sync_handler+0x144/0x168 [ 86.528367] el0t_64_sync+0x198/0x1a0 [ 86.528920] [ 86.529157] The buggy address belongs to the physical page: [ 86.529972] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff0000d46fd4d0 pfn:0x1146fc [ 86.531319] flags: 0xbfffc0000000000(node=0|zone=2|lastcpupid=0xffff) [ 86.532267] raw: 0bfffc0000000000 0000000000000000 dead000000000122 0000000000000000 [ 86.533390] raw: ffff0000d46fd4d0 0000000000000000 00000000ffffffff 0000000000000000 [ 86.534511] page dumped because: kasan: bad access detected [ 86.535323] [ 86.535559] Memory state around the buggy address: [ 86.536265] ffff0000d46fbf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.537314] ffff0000d46fbf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.538363] >ffff0000d46fc000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.544733] ^ [ 86.551057] ffff0000d46fc080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.557510] ffff0000d46fc100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.563928] ================================================================== [ 86.571093] Disabling lock debugging due to kernel taint [ 86.577642] Unable to handle kernel paging request at virtual address e0e9c0920000000b [ 86.581834] KASAN: maybe wild-memory-access in range [0x0752049000000058-0x075204900000005f] ... Signed-off-by: Guoqing Jiang <guoqing.jiang@canonical.com> --- drivers/gpu/drm/mediatek/mtk_drm_drv.c | 2 ++ 1 file changed, 2 insertions(+)