drivers/i2c/busses/i2c-amd-mp2-pci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
In i2c_amd_probe(), amd_mp2_find_device() utilizes
driver_find_next_device() which internally calls driver_find_device()
to locate the matching device. driver_find_device() increments the
reference count of the found device by calling get_device(), but
amd_mp2_find_device() fails to call put_device() to decrement the
reference count before returning. This results in a reference count
leak of the PCI device each time i2c_amd_probe() is executed, which
may prevent the device from being properly released and cause a memory
leak.
Found by code review.
Cc: stable@vger.kernel.org
Fixes: 529766e0a011 ("i2c: Add drivers for the AMD PCIe MP2 I2C controller")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
drivers/i2c/busses/i2c-amd-mp2-pci.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-amd-mp2-pci.c b/drivers/i2c/busses/i2c-amd-mp2-pci.c
index ef7370d3dbea..1f01d3f121ba 100644
--- a/drivers/i2c/busses/i2c-amd-mp2-pci.c
+++ b/drivers/i2c/busses/i2c-amd-mp2-pci.c
@@ -464,7 +464,9 @@ struct amd_mp2_dev *amd_mp2_find_device(void)
return NULL;
pci_dev = to_pci_dev(dev);
- return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
+ mp2_dev = (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
+ put_device(dev);
+ return mp2_dev;
}
EXPORT_SYMBOL_GPL(amd_mp2_find_device);
--
2.17.1Hi Ma,
kernel test robot noticed the following build errors:
[auto build test ERROR on andi-shyti/i2c/i2c-host]
[also build test ERROR on linus/master v6.17-rc7 next-20250926]
[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#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Ma-Ke/i2c-fix-reference-leak-in-MP2-PCI-device/20250927-190047
base: https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git i2c/i2c-host
patch link: https://lore.kernel.org/r/20250927105729.19164-1-make24%40iscas.ac.cn
patch subject: [PATCH] i2c: fix reference leak in MP2 PCI device
config: i386-randconfig-011-20250928 (https://download.01.org/0day-ci/archive/20250928/202509281317.3OLDoUnB-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250928/202509281317.3OLDoUnB-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509281317.3OLDoUnB-lkp@intel.com/
All errors (new ones prefixed by >>):
>> drivers/i2c/busses/i2c-amd-mp2-pci.c:467:2: error: use of undeclared identifier 'mp2_dev'
467 | mp2_dev = (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
| ^
drivers/i2c/busses/i2c-amd-mp2-pci.c:469:9: error: use of undeclared identifier 'mp2_dev'; did you mean 'pci_dev'?
469 | return mp2_dev;
| ^~~~~~~
| pci_dev
drivers/i2c/busses/i2c-amd-mp2-pci.c:460:18: note: 'pci_dev' declared here
460 | struct pci_dev *pci_dev;
| ^
>> drivers/i2c/busses/i2c-amd-mp2-pci.c:469:9: error: incompatible pointer types returning 'struct pci_dev *' from a function with result type 'struct amd_mp2_dev *' [-Werror,-Wincompatible-pointer-types]
469 | return mp2_dev;
| ^~~~~~~
3 errors generated.
vim +/mp2_dev +467 drivers/i2c/busses/i2c-amd-mp2-pci.c
456
457 struct amd_mp2_dev *amd_mp2_find_device(void)
458 {
459 struct device *dev;
460 struct pci_dev *pci_dev;
461
462 dev = driver_find_next_device(&amd_mp2_pci_driver.driver, NULL);
463 if (!dev)
464 return NULL;
465
466 pci_dev = to_pci_dev(dev);
> 467 mp2_dev = (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
468 put_device(dev);
> 469 return mp2_dev;
470 }
471 EXPORT_SYMBOL_GPL(amd_mp2_find_device);
472
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Ma,
kernel test robot noticed the following build warnings:
[auto build test WARNING on andi-shyti/i2c/i2c-host]
[also build test WARNING on linus/master v6.17-rc7 next-20250926]
[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#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Ma-Ke/i2c-fix-reference-leak-in-MP2-PCI-device/20250927-190047
base: https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git i2c/i2c-host
patch link: https://lore.kernel.org/r/20250927105729.19164-1-make24%40iscas.ac.cn
patch subject: [PATCH] i2c: fix reference leak in MP2 PCI device
config: i386-randconfig-013-20250928 (https://download.01.org/0day-ci/archive/20250928/202509281110.ACsS1CDz-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250928/202509281110.ACsS1CDz-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509281110.ACsS1CDz-lkp@intel.com/
All warnings (new ones prefixed by >>):
drivers/i2c/busses/i2c-amd-mp2-pci.c: In function 'amd_mp2_find_device':
drivers/i2c/busses/i2c-amd-mp2-pci.c:467:9: error: 'mp2_dev' undeclared (first use in this function)
467 | mp2_dev = (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
| ^~~~~~~
drivers/i2c/busses/i2c-amd-mp2-pci.c:467:9: note: each undeclared identifier is reported only once for each function it appears in
>> drivers/i2c/busses/i2c-amd-mp2-pci.c:470:1: warning: control reaches end of non-void function [-Wreturn-type]
470 | }
| ^
vim +470 drivers/i2c/busses/i2c-amd-mp2-pci.c
529766e0a01144 Elie Morisse 2019-03-05 456
529766e0a01144 Elie Morisse 2019-03-05 457 struct amd_mp2_dev *amd_mp2_find_device(void)
529766e0a01144 Elie Morisse 2019-03-05 458 {
529766e0a01144 Elie Morisse 2019-03-05 459 struct device *dev;
529766e0a01144 Elie Morisse 2019-03-05 460 struct pci_dev *pci_dev;
529766e0a01144 Elie Morisse 2019-03-05 461
6bf85ba9e55f65 Suzuki K Poulose 2019-07-23 462 dev = driver_find_next_device(&amd_mp2_pci_driver.driver, NULL);
529766e0a01144 Elie Morisse 2019-03-05 463 if (!dev)
529766e0a01144 Elie Morisse 2019-03-05 464 return NULL;
529766e0a01144 Elie Morisse 2019-03-05 465
529766e0a01144 Elie Morisse 2019-03-05 466 pci_dev = to_pci_dev(dev);
10a231ddf6f43e Ma Ke 2025-09-27 467 mp2_dev = (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
10a231ddf6f43e Ma Ke 2025-09-27 468 put_device(dev);
10a231ddf6f43e Ma Ke 2025-09-27 469 return mp2_dev;
529766e0a01144 Elie Morisse 2019-03-05 @470 }
529766e0a01144 Elie Morisse 2019-03-05 471 EXPORT_SYMBOL_GPL(amd_mp2_find_device);
529766e0a01144 Elie Morisse 2019-03-05 472
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
> In i2c_amd_probe(), amd_mp2_find_device() utilizes > driver_find_next_device() which internally calls driver_find_device() > to locate the matching device. driver_find_device() increments the > reference count of the found device by calling get_device(), but > amd_mp2_find_device() fails to call put_device() to decrement the > reference count before returning. This results in a reference count > leak of the PCI device each time i2c_amd_probe() is executed, which > may prevent the device from being properly released and cause a memory > leak. How do you think about to increase the application of scope-based resource management? https://elixir.bootlin.com/linux/v6.17-rc7/source/include/linux/device.h#L1180 Regards, Markus
On Sat, Sep 27, 2025 at 02:56:49PM +0200, Markus Elfring wrote: > > In i2c_amd_probe(), amd_mp2_find_device() utilizes > > driver_find_next_device() which internally calls driver_find_device() > > to locate the matching device. driver_find_device() increments the > > reference count of the found device by calling get_device(), but > > amd_mp2_find_device() fails to call put_device() to decrement the > > reference count before returning. This results in a reference count > > leak of the PCI device each time i2c_amd_probe() is executed, which > > may prevent the device from being properly released and cause a memory > > leak. > > How do you think about to increase the application of scope-based resource management? > https://elixir.bootlin.com/linux/v6.17-rc7/source/include/linux/device.h#L1180 > > Regards, > Markus > Hi, This is the semi-friendly patch-bot of Greg Kroah-Hartman. Markus, you seem to have sent a nonsensical or otherwise pointless review comment to a patch submission on a Linux kernel developer mailing list. I strongly suggest that you not do this anymore. Please do not bother developers who are actively working to produce patches and features with comments that, in the end, are a waste of time. Patch submitter, please ignore Markus's suggestion; you do not need to follow it at all. The person/bot/AI that sent it is being ignored by almost all Linux kernel maintainers for having a persistent pattern of behavior of producing distracting and pointless commentary, and inability to adapt to feedback. Please feel free to also ignore emails from them. thanks, greg k-h's patch email bot
© 2016 - 2025 Red Hat, Inc.