| Message ID | 20241025060942.1049263-1-chenridong@huaweicloud.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] mm: shrinker: avoid memleak in alloc_shrinker_info | expand |
On 2024/10/25 14:09, Chen Ridong wrote: > From: Chen Ridong <chenridong@huawei.com> > > A memleak was found as bellow: > > unreferenced object 0xffff8881010d2a80 (size 32): > comm "mkdir", pid 1559, jiffies 4294932666 > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 @............... > backtrace (crc 2e7ef6fa): > [<ffffffff81372754>] __kmalloc_node_noprof+0x394/0x470 > [<ffffffff813024ab>] alloc_shrinker_info+0x7b/0x1a0 > [<ffffffff813b526a>] mem_cgroup_css_online+0x11a/0x3b0 > [<ffffffff81198dd9>] online_css+0x29/0xa0 > [<ffffffff811a243d>] cgroup_apply_control_enable+0x20d/0x360 > [<ffffffff811a5728>] cgroup_mkdir+0x168/0x5f0 > [<ffffffff8148543e>] kernfs_iop_mkdir+0x5e/0x90 > [<ffffffff813dbb24>] vfs_mkdir+0x144/0x220 > [<ffffffff813e1c97>] do_mkdirat+0x87/0x130 > [<ffffffff813e1de9>] __x64_sys_mkdir+0x49/0x70 > [<ffffffff81f8c928>] do_syscall_64+0x68/0x140 > [<ffffffff8200012f>] entry_SYSCALL_64_after_hwframe+0x76/0x7e > > In the alloc_shrinker_info function, when shrinker_unit_alloc return > err, the info won't be freed. Just fix it. > > Fixes: 307bececcd12 ("mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}") Again, please: Cc: stable@vger.kernel.org I think Andrew can help add that. ;) Thanks! > Signed-off-by: Chen Ridong <chenridong@huawei.com> > Acked-by: Qi Zheng <zhengqi.arch@bytedance.com> > Acked-by: Roman Gushchin <roman.gushchin@linux.dev> > Acked-by: Vlastimil Babka <vbabka@suse.cz> > --- > mm/shrinker.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/mm/shrinker.c b/mm/shrinker.c > index dc5d2a6fcfc4..4a93fd433689 100644 > --- a/mm/shrinker.c > +++ b/mm/shrinker.c > @@ -76,19 +76,21 @@ void free_shrinker_info(struct mem_cgroup *memcg) > > int alloc_shrinker_info(struct mem_cgroup *memcg) > { > - struct shrinker_info *info; > int nid, ret = 0; > int array_size = 0; > > mutex_lock(&shrinker_mutex); > array_size = shrinker_unit_size(shrinker_nr_max); > for_each_node(nid) { > - info = kvzalloc_node(sizeof(*info) + array_size, GFP_KERNEL, nid); > + struct shrinker_info *info = kvzalloc_node(sizeof(*info) + array_size, > + GFP_KERNEL, nid); > if (!info) > goto err; > info->map_nr_max = shrinker_nr_max; > - if (shrinker_unit_alloc(info, NULL, nid)) > + if (shrinker_unit_alloc(info, NULL, nid)) { > + kvfree(info); > goto err; > + } > rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info); > } > mutex_unlock(&shrinker_mutex);
On Fri, Oct 25, 2024 at 06:09:42AM +0000, Chen Ridong wrote: > From: Chen Ridong <chenridong@huawei.com> > > A memleak was found as bellow: > > unreferenced object 0xffff8881010d2a80 (size 32): > comm "mkdir", pid 1559, jiffies 4294932666 > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 @............... > backtrace (crc 2e7ef6fa): > [<ffffffff81372754>] __kmalloc_node_noprof+0x394/0x470 > [<ffffffff813024ab>] alloc_shrinker_info+0x7b/0x1a0 > [<ffffffff813b526a>] mem_cgroup_css_online+0x11a/0x3b0 > [<ffffffff81198dd9>] online_css+0x29/0xa0 > [<ffffffff811a243d>] cgroup_apply_control_enable+0x20d/0x360 > [<ffffffff811a5728>] cgroup_mkdir+0x168/0x5f0 > [<ffffffff8148543e>] kernfs_iop_mkdir+0x5e/0x90 > [<ffffffff813dbb24>] vfs_mkdir+0x144/0x220 > [<ffffffff813e1c97>] do_mkdirat+0x87/0x130 > [<ffffffff813e1de9>] __x64_sys_mkdir+0x49/0x70 > [<ffffffff81f8c928>] do_syscall_64+0x68/0x140 > [<ffffffff8200012f>] entry_SYSCALL_64_after_hwframe+0x76/0x7e This dump doesn't add much value to the commit message. > In the alloc_shrinker_info function, when shrinker_unit_alloc return > err, the info won't be freed. Just fix it. > > Fixes: 307bececcd12 ("mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}") > Signed-off-by: Chen Ridong <chenridong@huawei.com> > Acked-by: Qi Zheng <zhengqi.arch@bytedance.com> > Acked-by: Roman Gushchin <roman.gushchin@linux.dev> > Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
diff --git a/mm/shrinker.c b/mm/shrinker.c index dc5d2a6fcfc4..4a93fd433689 100644 --- a/mm/shrinker.c +++ b/mm/shrinker.c @@ -76,19 +76,21 @@ void free_shrinker_info(struct mem_cgroup *memcg) int alloc_shrinker_info(struct mem_cgroup *memcg) { - struct shrinker_info *info; int nid, ret = 0; int array_size = 0; mutex_lock(&shrinker_mutex); array_size = shrinker_unit_size(shrinker_nr_max); for_each_node(nid) { - info = kvzalloc_node(sizeof(*info) + array_size, GFP_KERNEL, nid); + struct shrinker_info *info = kvzalloc_node(sizeof(*info) + array_size, + GFP_KERNEL, nid); if (!info) goto err; info->map_nr_max = shrinker_nr_max; - if (shrinker_unit_alloc(info, NULL, nid)) + if (shrinker_unit_alloc(info, NULL, nid)) { + kvfree(info); goto err; + } rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info); } mutex_unlock(&shrinker_mutex);