| Message ID | 20240819062045.1481298-1-lizhijian@fujitsu.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 62c2aa6b1f565d2fc1ec11a6e9e8336ce37a6426 |
| Delegated to: | Ira Weiny |
| Headers | show |
| Series | [v3,1/2] nvdimm: Fix devs leaks in scan_labels() | expand |
Li Zhijian wrote: > scan_labels() leaks memory when label scanning fails and it falls back > to just creating a default "seed" namespace for userspace to configure. > Root can force the kernel to leak memory. > > Allocate the minimum resources unconditionally and release them when > unneeded to avoid the memory leak. > > A kmemleak reports: > unreferenced object 0xffff88800dda1980 (size 16): > comm "kworker/u10:5", pid 69, jiffies 4294671781 > hex dump (first 16 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace (crc 0): > [<00000000c5dea560>] __kmalloc+0x32c/0x470 > [<000000009ed43c83>] nd_region_register_namespaces+0x6fb/0x1120 [libnvdimm] > [<000000000e07a65c>] nd_region_probe+0xfe/0x210 [libnvdimm] > [<000000007b79ce5f>] nvdimm_bus_probe+0x7a/0x1e0 [libnvdimm] > [<00000000a5f3da2e>] really_probe+0xc6/0x390 > [<00000000129e2a69>] __driver_probe_device+0x78/0x150 > [<000000002dfed28b>] driver_probe_device+0x1e/0x90 > [<00000000e7048de2>] __device_attach_driver+0x85/0x110 > [<0000000032dca295>] bus_for_each_drv+0x85/0xe0 > [<00000000391c5a7d>] __device_attach+0xbe/0x1e0 > [<0000000026dabec0>] bus_probe_device+0x94/0xb0 > [<00000000c590d936>] device_add+0x656/0x870 > [<000000003d69bfaa>] nd_async_device_register+0xe/0x50 [libnvdimm] > [<000000003f4c52a4>] async_run_entry_fn+0x2e/0x110 > [<00000000e201f4b0>] process_one_work+0x1ee/0x600 > [<000000006d90d5a9>] worker_thread+0x183/0x350 > > Cc: Dave Jiang <dave.jiang@intel.com> > Cc: Ira Weiny <ira.weiny@intel.com> > Fixes: 1b40e09a1232 ("libnvdimm: blk labels and namespace instantiation") > Suggested-by: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> > Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> > --- > V3: > update commit log and allocate the minimum(2 *dev) unconditionally. # Dan > > V2: > update description and comment > Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> > --- > drivers/nvdimm/namespace_devs.c | 34 ++++++++++++++++----------------- > 1 file changed, 17 insertions(+), 17 deletions(-) > > diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c > index d6d558f94d6b..35d9f3cc2efa 100644 > --- a/drivers/nvdimm/namespace_devs.c > +++ b/drivers/nvdimm/namespace_devs.c > @@ -1937,12 +1937,16 @@ static int cmp_dpa(const void *a, const void *b) > static struct device **scan_labels(struct nd_region *nd_region) > { > int i, count = 0; > - struct device *dev, **devs = NULL; > + struct device *dev, **devs; > struct nd_label_ent *label_ent, *e; > struct nd_mapping *nd_mapping = &nd_region->mapping[0]; > struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); > resource_size_t map_end = nd_mapping->start + nd_mapping->size - 1; > > + devs = kcalloc(2, sizeof(dev), GFP_KERNEL); > + if (!devs) > + return NULL; > + > /* "safe" because create_namespace_pmem() might list_move() label_ent */ > list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list) { > struct nd_namespace_label *nd_label = label_ent->label; > @@ -1961,12 +1965,14 @@ static struct device **scan_labels(struct nd_region *nd_region) > goto err; > if (i < count) > continue; > - __devs = kcalloc(count + 2, sizeof(dev), GFP_KERNEL); > - if (!__devs) > - goto err; > - memcpy(__devs, devs, sizeof(dev) * count); > - kfree(devs); > - devs = __devs; > + if (count) { > + __devs = kcalloc(count + 2, sizeof(dev), GFP_KERNEL); > + if (!__devs) > + goto err; > + memcpy(__devs, devs, sizeof(dev) * count); > + kfree(devs); > + devs = __devs; > + } > > dev = create_namespace_pmem(nd_region, nd_mapping, nd_label); > if (IS_ERR(dev)) { > @@ -1993,11 +1999,6 @@ static struct device **scan_labels(struct nd_region *nd_region) > > /* Publish a zero-sized namespace for userspace to configure. */ > nd_mapping_free_labels(nd_mapping); > - > - devs = kcalloc(2, sizeof(dev), GFP_KERNEL); > - if (!devs) > - goto err; > - > nspm = kzalloc(sizeof(*nspm), GFP_KERNEL); > if (!nspm) > goto err; > @@ -2036,11 +2037,10 @@ static struct device **scan_labels(struct nd_region *nd_region) > return devs; > > err: > - if (devs) { > - for (i = 0; devs[i]; i++) > - namespace_pmem_release(devs[i]); > - kfree(devs); > - } > + for (i = 0; devs[i]; i++) > + namespace_pmem_release(devs[i]); > + kfree(devs); > + > return NULL; > } > > -- > 2.29.2 >
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index d6d558f94d6b..35d9f3cc2efa 100644 --- a/drivers/nvdimm/namespace_devs.c +++ b/drivers/nvdimm/namespace_devs.c @@ -1937,12 +1937,16 @@ static int cmp_dpa(const void *a, const void *b) static struct device **scan_labels(struct nd_region *nd_region) { int i, count = 0; - struct device *dev, **devs = NULL; + struct device *dev, **devs; struct nd_label_ent *label_ent, *e; struct nd_mapping *nd_mapping = &nd_region->mapping[0]; struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); resource_size_t map_end = nd_mapping->start + nd_mapping->size - 1; + devs = kcalloc(2, sizeof(dev), GFP_KERNEL); + if (!devs) + return NULL; + /* "safe" because create_namespace_pmem() might list_move() label_ent */ list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list) { struct nd_namespace_label *nd_label = label_ent->label; @@ -1961,12 +1965,14 @@ static struct device **scan_labels(struct nd_region *nd_region) goto err; if (i < count) continue; - __devs = kcalloc(count + 2, sizeof(dev), GFP_KERNEL); - if (!__devs) - goto err; - memcpy(__devs, devs, sizeof(dev) * count); - kfree(devs); - devs = __devs; + if (count) { + __devs = kcalloc(count + 2, sizeof(dev), GFP_KERNEL); + if (!__devs) + goto err; + memcpy(__devs, devs, sizeof(dev) * count); + kfree(devs); + devs = __devs; + } dev = create_namespace_pmem(nd_region, nd_mapping, nd_label); if (IS_ERR(dev)) { @@ -1993,11 +1999,6 @@ static struct device **scan_labels(struct nd_region *nd_region) /* Publish a zero-sized namespace for userspace to configure. */ nd_mapping_free_labels(nd_mapping); - - devs = kcalloc(2, sizeof(dev), GFP_KERNEL); - if (!devs) - goto err; - nspm = kzalloc(sizeof(*nspm), GFP_KERNEL); if (!nspm) goto err; @@ -2036,11 +2037,10 @@ static struct device **scan_labels(struct nd_region *nd_region) return devs; err: - if (devs) { - for (i = 0; devs[i]; i++) - namespace_pmem_release(devs[i]); - kfree(devs); - } + for (i = 0; devs[i]; i++) + namespace_pmem_release(devs[i]); + kfree(devs); + return NULL; }
scan_labels() leaks memory when label scanning fails and it falls back to just creating a default "seed" namespace for userspace to configure. Root can force the kernel to leak memory. Allocate the minimum resources unconditionally and release them when unneeded to avoid the memory leak. A kmemleak reports: unreferenced object 0xffff88800dda1980 (size 16): comm "kworker/u10:5", pid 69, jiffies 4294671781 hex dump (first 16 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc 0): [<00000000c5dea560>] __kmalloc+0x32c/0x470 [<000000009ed43c83>] nd_region_register_namespaces+0x6fb/0x1120 [libnvdimm] [<000000000e07a65c>] nd_region_probe+0xfe/0x210 [libnvdimm] [<000000007b79ce5f>] nvdimm_bus_probe+0x7a/0x1e0 [libnvdimm] [<00000000a5f3da2e>] really_probe+0xc6/0x390 [<00000000129e2a69>] __driver_probe_device+0x78/0x150 [<000000002dfed28b>] driver_probe_device+0x1e/0x90 [<00000000e7048de2>] __device_attach_driver+0x85/0x110 [<0000000032dca295>] bus_for_each_drv+0x85/0xe0 [<00000000391c5a7d>] __device_attach+0xbe/0x1e0 [<0000000026dabec0>] bus_probe_device+0x94/0xb0 [<00000000c590d936>] device_add+0x656/0x870 [<000000003d69bfaa>] nd_async_device_register+0xe/0x50 [libnvdimm] [<000000003f4c52a4>] async_run_entry_fn+0x2e/0x110 [<00000000e201f4b0>] process_one_work+0x1ee/0x600 [<000000006d90d5a9>] worker_thread+0x183/0x350 Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Fixes: 1b40e09a1232 ("libnvdimm: blk labels and namespace instantiation") Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> --- V3: update commit log and allocate the minimum(2 *dev) unconditionally. # Dan V2: update description and comment Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> --- drivers/nvdimm/namespace_devs.c | 34 ++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-)