| Message ID | 20220422223549.4173-1-miles.chen@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iommu/mediatek: fix NULL pointer dereference when printing dev_name | expand |
Hi Miles,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on joro-iommu/next]
[also build test WARNING on v5.18-rc3 next-20220422]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Miles-Chen/iommu-mediatek-fix-NULL-pointer-dereference-when-printing-dev_name/20220423-070605
base: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next
config: hexagon-randconfig-r041-20220422 (https://download.01.org/0day-ci/archive/20220423/202204231446.IYKdZ674-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 5bd87350a5ae429baf8f373cb226a57b62f87280)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/85771767e503ca60069fe4e6ec2ddb80c7f9bafa
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Miles-Chen/iommu-mediatek-fix-NULL-pointer-dereference-when-printing-dev_name/20220423-070605
git checkout 85771767e503ca60069fe4e6ec2ddb80c7f9bafa
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/iommu/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> drivers/iommu/mtk_iommu.c:605:6: warning: variable 'larbdev' is uninitialized when used here [-Wuninitialized]
if (larbdev) {
^~~~~~~
drivers/iommu/mtk_iommu.c:597:24: note: initialize the variable 'larbdev' to silence this warning
struct device *larbdev;
^
= NULL
1 warning generated.
vim +/larbdev +605 drivers/iommu/mtk_iommu.c
592
593 static void mtk_iommu_release_device(struct device *dev)
594 {
595 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
596 struct mtk_iommu_data *data;
597 struct device *larbdev;
598 unsigned int larbid;
599
600 if (!fwspec || fwspec->ops != &mtk_iommu_ops)
601 return;
602
603 data = dev_iommu_priv_get(dev);
604 larbid = MTK_M4U_TO_LARB(fwspec->ids[0]);
> 605 if (larbdev) {
606 larbdev = data->larb_imu[larbid].dev;
607 device_link_remove(dev, larbdev);
608 }
609
610 iommu_fwspec_free(dev);
611 }
612
>Hi Miles, > >Thank you for the patch! Perhaps something to improve: > >[auto build test WARNING on joro-iommu/next] >[also build test WARNING on v5.18-rc3 next-20220422] >[If your patch is applied to the wrong git tree, kindly drop us a note. >And when submitting patch, we suggest to use '--base' as documented in >https://git-scm.com/docs/git-format-patch] > >url: https://github.com/intel-lab-lkp/linux/commits/Miles-Chen/iommu-mediatek-fix-NULL-pointer-dereference-when-printing-dev_name/20220423-070605 >base: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next >config: hexagon-randconfig-r041-20220422 (https://download.01.org/0day-ci/archive/20220423/202204231446.IYKdZ674-lkp@intel.com/config) >compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 5bd87350a5ae429baf8f373cb226a57b62f87280) >reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # https://github.com/intel-lab-lkp/linux/commit/85771767e503ca60069fe4e6ec2ddb80c7f9bafa > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Miles-Chen/iommu-mediatek-fix-NULL-pointer-dereference-when-printing-dev_name/20220423-070605 > git checkout 85771767e503ca60069fe4e6ec2ddb80c7f9bafa > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/iommu/ > >If you fix the issue, kindly add following tag as appropriate >Reported-by: kernel test robot <lkp@intel.com> > >All warnings (new ones prefixed by >>): > >>> drivers/iommu/mtk_iommu.c:605:6: warning: variable 'larbdev' is uninitialized when used here [-Wuninitialized] > if (larbdev) { > ^~~~~~~ > drivers/iommu/mtk_iommu.c:597:24: note: initialize the variable 'larbdev' to silence this warning > struct device *larbdev; > ^ > = NULL > 1 warning generated. Thanks for catching this, I will fix this in next version. thanks, Miles
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 6fd75a60abd6..1405502118ca 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -581,10 +581,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -600,8 +602,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = MTK_M4U_TO_LARB(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); } diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index ecff800656e6..d46b147afcf0 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -467,10 +467,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -501,8 +503,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = mt2701_m4u_to_larb(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); }
When larbdev is NULL (in the case I hit, the node is incorrectly set iommus = <&iommu NUM>), it will cause device_link_add() fail and the kernel crashes when we try to print dev_name(larbdev). Fix it by adding a NULL pointer check before device_link_add/device_link_remove. It should work for normal correct setting and avoid the crash caused by my incorrect setting. Error log: [ 18.189042][ T301] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050 [ 18.190247][ T301] Mem abort info: [ 18.190255][ T301] ESR = 0x96000005 [ 18.190263][ T301] EC = 0x25: DABT (current EL), IL = 32 bits [ 18.192142][ T301] SET = 0, FnV = 0 [ 18.192151][ T301] EA = 0, S1PTW = 0 [ 18.194710][ T301] FSC = 0x05: level 1 translation fault [ 18.195424][ T301] Data abort info: [ 18.195888][ T301] ISV = 0, ISS = 0x00000005 [ 18.196500][ T301] CM = 0, WnR = 0 [ 18.196977][ T301] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000104f9e000 [ 18.197889][ T301] [0000000000000050] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 18.199220][ T301] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 18.343152][ T301] Kernel Offset: 0x1444080000 from 0xffffffc008000000 [ 18.343988][ T301] PHYS_OFFSET: 0x40000000 [ 18.344519][ T301] pstate: a0400005 (NzCv daif +PAN -UAO) [ 18.345213][ T301] pc : mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu] [ 18.346050][ T301] lr : mtk_iommu_probe_device+0xd0/0x118 [mtk_iommu] [ 18.346884][ T301] sp : ffffffc00a5635e0 [ 18.347392][ T301] x29: ffffffc00a5635e0 x28: ffffffd44a46c1d8 [ 18.348156][ T301] x27: ffffff80c39a8000 x26: ffffffd44a80cc38 [ 18.348917][ T301] x25: 0000000000000000 x24: ffffffd44a80cc38 [ 18.349677][ T301] x23: ffffffd44e4da4c6 x22: ffffffd44a80cc38 [ 18.350438][ T301] x21: ffffff80cecd1880 x20: 0000000000000000 [ 18.351198][ T301] x19: ffffff80c439f010 x18: ffffffc00a50d0c0 [ 18.351959][ T301] x17: ffffffffffffffff x16: 0000000000000004 [ 18.352719][ T301] x15: 0000000000000004 x14: ffffffd44eb5d420 [ 18.353480][ T301] x13: 0000000000000ad2 x12: 0000000000000003 [ 18.354241][ T301] x11: 00000000fffffad2 x10: c0000000fffffad2 [ 18.355003][ T301] x9 : a0d288d8d7142d00 x8 : a0d288d8d7142d00 [ 18.355763][ T301] x7 : ffffffd44c2bc640 x6 : 0000000000000000 [ 18.356524][ T301] x5 : 0000000000000080 x4 : 0000000000000001 [ 18.357284][ T301] x3 : 0000000000000000 x2 : 0000000000000005 [ 18.358045][ T301] x1 : 0000000000000000 x0 : 0000000000000000 [ 18.360208][ T301] Hardware name: MT6873 (DT) [ 18.360771][ T301] Call trace: [ 18.361168][ T301] dump_backtrace+0xf8/0x1f0 [ 18.361737][ T301] dump_stack_lvl+0xa8/0x11c [ 18.362305][ T301] dump_stack+0x1c/0x2c [ 18.362816][ T301] mrdump_common_die+0x184/0x40c [mrdump] [ 18.363575][ T301] ipanic_die+0x24/0x38 [mrdump] [ 18.364230][ T301] atomic_notifier_call_chain+0x128/0x2b8 [ 18.364937][ T301] die+0x16c/0x568 [ 18.365394][ T301] __do_kernel_fault+0x1e8/0x214 [ 18.365402][ T301] do_page_fault+0xb8/0x678 [ 18.366934][ T301] do_translation_fault+0x48/0x64 [ 18.368645][ T301] do_mem_abort+0x68/0x148 [ 18.368652][ T301] el1_abort+0x40/0x64 [ 18.368660][ T301] el1h_64_sync_handler+0x54/0x88 [ 18.368668][ T301] el1h_64_sync+0x68/0x6c [ 18.368673][ T301] mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu] [ 18.369840][ T301] __iommu_probe_device+0x12c/0x358 [ 18.370880][ T301] iommu_probe_device+0x3c/0x31c [ 18.372026][ T301] of_iommu_configure+0x200/0x274 [ 18.373587][ T301] of_dma_configure_id+0x1b8/0x230 [ 18.375200][ T301] platform_dma_configure+0x24/0x3c [ 18.376456][ T301] really_probe+0x110/0x504 [ 18.376464][ T301] __driver_probe_device+0xb4/0x188 [ 18.376472][ T301] driver_probe_device+0x5c/0x2b8 [ 18.376481][ T301] __driver_attach+0x338/0x42c [ 18.377992][ T301] bus_add_driver+0x218/0x4c8 [ 18.379389][ T301] driver_register+0x84/0x17c [ 18.380580][ T301] __platform_driver_register+0x28/0x38 ... Fixes: 635319a4a744 ("media: iommu/mediatek: Add device_link between the consumer and the larb devices") Signed-off-by: Miles Chen <miles.chen@mediatek.com> --- drivers/iommu/mtk_iommu.c | 16 ++++++++++------ drivers/iommu/mtk_iommu_v1.c | 16 ++++++++++------ 2 files changed, 20 insertions(+), 12 deletions(-)