| Message ID | 20241011095512.3667549-1-ruanjinjie@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | iio: gts-helper: Fix memory leaks in iio_gts_build_avail_scale_table() | expand |
On Fri, 11 Oct 2024 17:55:12 +0800 Jinjie Ruan <ruanjinjie@huawei.com> wrote: > modprobe iio-test-gts and rmmod it, then the following memory leak > occurs: > > unreferenced object 0xffffff80c810be00 (size 64): > comm "kunit_try_catch", pid 1654, jiffies 4294913981 > hex dump (first 32 bytes): > 02 00 00 00 08 00 00 00 20 00 00 00 40 00 00 00 ........ ...@... > 80 00 00 00 00 02 00 00 00 04 00 00 00 08 00 00 ................ > backtrace (crc a63d875e): > [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40 > [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0 > [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4 > [<0000000071bb4b09>] 0xffffffdf052a62e0 > [<000000000315bc18>] 0xffffffdf052a6488 > [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac > [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec > [<00000000f505065d>] kthread+0x2e8/0x374 > [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20 > unreferenced object 0xffffff80cbfe9e70 (size 16): > comm "kunit_try_catch", pid 1658, jiffies 4294914015 > hex dump (first 16 bytes): > 10 00 00 00 40 00 00 00 80 00 00 00 00 00 00 00 ....@........... > backtrace (crc 857f0cb4): > [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40 > [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0 > [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4 > [<0000000071bb4b09>] 0xffffffdf052a62e0 > [<000000007d089d45>] 0xffffffdf052a6864 > [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac > [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec > [<00000000f505065d>] kthread+0x2e8/0x374 > [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20 > ...... > > It includes 5*5 times "size 64" memory leaks, which correspond to 5 times > test_init_iio_gain_scale() calls with gts_test_gains size 10 (10*size(int)) > and gts_test_itimes size 5. It also includes 5*1 times "size 16" > memory leak, which correspond to one time __test_init_iio_gain_scale() > call with gts_test_gains_gain_low size 3 (3*size(int)) and gts_test_itimes > size 5. > > The reason is that the per_time_gains[i] is not freed which is allocated in > the "gts->num_itime" for loop in iio_gts_build_avail_scale_table(). > > Cc: stable@vger.kernel.org > Fixes: 38416c28e168 ("iio: light: Add gain-time-scale helpers") > Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Hi Jinjie, Your explanation looks correct to me. I'll wait a while though to give Matti time to take a look as well. Thanks, Jonathan > --- > drivers/iio/industrialio-gts-helper.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c > index 59d7615c0f56..7326c7949244 100644 > --- a/drivers/iio/industrialio-gts-helper.c > +++ b/drivers/iio/industrialio-gts-helper.c > @@ -307,6 +307,8 @@ static int iio_gts_build_avail_scale_table(struct iio_gts *gts) > if (ret) > goto err_free_out; > > + for (i = 0; i < gts->num_itime; i++) > + kfree(per_time_gains[i]); > kfree(per_time_gains); > gts->per_time_avail_scale_tables = per_time_scales; >
Hi Jinjie, Jonathan, On 12/10/2024 19:15, Jonathan Cameron wrote: > On Fri, 11 Oct 2024 17:55:12 +0800 > Jinjie Ruan <ruanjinjie@huawei.com> wrote: > >> modprobe iio-test-gts and rmmod it, then the following memory leak >> occurs: >> >> unreferenced object 0xffffff80c810be00 (size 64): >> comm "kunit_try_catch", pid 1654, jiffies 4294913981 >> hex dump (first 32 bytes): >> 02 00 00 00 08 00 00 00 20 00 00 00 40 00 00 00 ........ ...@... >> 80 00 00 00 00 02 00 00 00 04 00 00 00 08 00 00 ................ >> backtrace (crc a63d875e): >> [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40 >> [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0 >> [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4 >> [<0000000071bb4b09>] 0xffffffdf052a62e0 >> [<000000000315bc18>] 0xffffffdf052a6488 >> [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac >> [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec >> [<00000000f505065d>] kthread+0x2e8/0x374 >> [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20 >> unreferenced object 0xffffff80cbfe9e70 (size 16): >> comm "kunit_try_catch", pid 1658, jiffies 4294914015 >> hex dump (first 16 bytes): >> 10 00 00 00 40 00 00 00 80 00 00 00 00 00 00 00 ....@........... >> backtrace (crc 857f0cb4): >> [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40 >> [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0 >> [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4 >> [<0000000071bb4b09>] 0xffffffdf052a62e0 >> [<000000007d089d45>] 0xffffffdf052a6864 >> [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac >> [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec >> [<00000000f505065d>] kthread+0x2e8/0x374 >> [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20 >> ...... >> >> It includes 5*5 times "size 64" memory leaks, which correspond to 5 times >> test_init_iio_gain_scale() calls with gts_test_gains size 10 (10*size(int)) >> and gts_test_itimes size 5. It also includes 5*1 times "size 16" >> memory leak, which correspond to one time __test_init_iio_gain_scale() >> call with gts_test_gains_gain_low size 3 (3*size(int)) and gts_test_itimes >> size 5. >> >> The reason is that the per_time_gains[i] is not freed which is allocated in >> the "gts->num_itime" for loop in iio_gts_build_avail_scale_table(). >> >> Cc: stable@vger.kernel.org >> Fixes: 38416c28e168 ("iio: light: Add gain-time-scale helpers") >> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> > Hi Jinjie, > > Your explanation looks correct to me. I'll wait a while though to give Matti time > to take a look as well. Sorry for late reply - I spent last couple of days walking through the swamps and forests in the wilderness. Something was bothering me with this. I browsed through the code and all the allocations and I'm not able to see why these arrays shouldn't be freed. I did even go through the versions I've sent on list trying to find out what bothers me. Well, I found nothing. The version 2 had some code which looped through these arrays freeing them - in an error path - but not in successful case. It seemed as if I had thought these values had to be maintained - but I really can't see why. So - thanks. I suppose leaving the memory not freed is just a bug :) Nice that you killed this one :) Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com> > > Thanks, > > Jonathan > >> --- >> drivers/iio/industrialio-gts-helper.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c >> index 59d7615c0f56..7326c7949244 100644 >> --- a/drivers/iio/industrialio-gts-helper.c >> +++ b/drivers/iio/industrialio-gts-helper.c >> @@ -307,6 +307,8 @@ static int iio_gts_build_avail_scale_table(struct iio_gts *gts) >> if (ret) >> goto err_free_out; >> >> + for (i = 0; i < gts->num_itime; i++) >> + kfree(per_time_gains[i]); >> kfree(per_time_gains); >> gts->per_time_avail_scale_tables = per_time_scales; >> >
diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c index 59d7615c0f56..7326c7949244 100644 --- a/drivers/iio/industrialio-gts-helper.c +++ b/drivers/iio/industrialio-gts-helper.c @@ -307,6 +307,8 @@ static int iio_gts_build_avail_scale_table(struct iio_gts *gts) if (ret) goto err_free_out; + for (i = 0; i < gts->num_itime; i++) + kfree(per_time_gains[i]); kfree(per_time_gains); gts->per_time_avail_scale_tables = per_time_scales;
modprobe iio-test-gts and rmmod it, then the following memory leak occurs: unreferenced object 0xffffff80c810be00 (size 64): comm "kunit_try_catch", pid 1654, jiffies 4294913981 hex dump (first 32 bytes): 02 00 00 00 08 00 00 00 20 00 00 00 40 00 00 00 ........ ...@... 80 00 00 00 00 02 00 00 00 04 00 00 00 08 00 00 ................ backtrace (crc a63d875e): [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40 [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0 [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4 [<0000000071bb4b09>] 0xffffffdf052a62e0 [<000000000315bc18>] 0xffffffdf052a6488 [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec [<00000000f505065d>] kthread+0x2e8/0x374 [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20 unreferenced object 0xffffff80cbfe9e70 (size 16): comm "kunit_try_catch", pid 1658, jiffies 4294914015 hex dump (first 16 bytes): 10 00 00 00 40 00 00 00 80 00 00 00 00 00 00 00 ....@........... backtrace (crc 857f0cb4): [<0000000028c1b3c2>] kmemleak_alloc+0x34/0x40 [<000000001d6ecc87>] __kmalloc_noprof+0x2bc/0x3c0 [<00000000393795c1>] devm_iio_init_iio_gts+0x4b4/0x16f4 [<0000000071bb4b09>] 0xffffffdf052a62e0 [<000000007d089d45>] 0xffffffdf052a6864 [<00000000f9dc55b5>] kunit_try_run_case+0x13c/0x3ac [<00000000175a3fd4>] kunit_generic_run_threadfn_adapter+0x80/0xec [<00000000f505065d>] kthread+0x2e8/0x374 [<00000000bbfb0e5d>] ret_from_fork+0x10/0x20 ...... It includes 5*5 times "size 64" memory leaks, which correspond to 5 times test_init_iio_gain_scale() calls with gts_test_gains size 10 (10*size(int)) and gts_test_itimes size 5. It also includes 5*1 times "size 16" memory leak, which correspond to one time __test_init_iio_gain_scale() call with gts_test_gains_gain_low size 3 (3*size(int)) and gts_test_itimes size 5. The reason is that the per_time_gains[i] is not freed which is allocated in the "gts->num_itime" for loop in iio_gts_build_avail_scale_table(). Cc: stable@vger.kernel.org Fixes: 38416c28e168 ("iio: light: Add gain-time-scale helpers") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- drivers/iio/industrialio-gts-helper.c | 2 ++ 1 file changed, 2 insertions(+)