diff options
| author | Nanyong Sun <sunnanyong@huawei.com> | 2021-09-07 20:00:09 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-08 11:50:27 -0700 |
| commit | 5f5dec07aca7067216ed4c1342e464e7307a9197 (patch) | |
| tree | 3747ccbd29e9243c798abfcc3c56d8da13c7a346 /fs/nilfs2 | |
| parent | 8b097881b54cbc23dd78262ed88c9924d00ea457 (diff) | |
nilfs2: fix memory leak in nilfs_sysfs_create_device_group
Patch series "nilfs2: fix incorrect usage of kobject".
This patchset from Nanyong Sun fixes memory leak issues and a NULL
pointer dereference issue caused by incorrect usage of kboject in nilfs2
sysfs implementation.
This patch (of 6):
Reported by syzkaller:
BUG: memory leak
unreferenced object 0xffff888100ca8988 (size 8):
comm "syz-executor.1", pid 1930, jiffies 4294745569 (age 18.052s)
hex dump (first 8 bytes):
6c 6f 6f 70 31 00 ff ff loop1...
backtrace:
kstrdup+0x36/0x70 mm/util.c:60
kstrdup_const+0x35/0x60 mm/util.c:83
kvasprintf_const+0xf1/0x180 lib/kasprintf.c:48
kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289
kobject_add_varg lib/kobject.c:384 [inline]
kobject_init_and_add+0xc9/0x150 lib/kobject.c:473
nilfs_sysfs_create_device_group+0x150/0x7d0 fs/nilfs2/sysfs.c:986
init_nilfs+0xa21/0xea0 fs/nilfs2/the_nilfs.c:637
nilfs_fill_super fs/nilfs2/super.c:1046 [inline]
nilfs_mount+0x7b4/0xe80 fs/nilfs2/super.c:1316
legacy_get_tree+0x105/0x210 fs/fs_context.c:592
vfs_get_tree+0x8e/0x2d0 fs/super.c:1498
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0xf9b/0x1990 fs/namespace.c:3235
do_mount+0xea/0x100 fs/namespace.c:3248
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount fs/namespace.c:3433 [inline]
__x64_sys_mount+0x14b/0x1f0 fs/namespace.c:3433
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
If kobject_init_and_add return with error, then the cleanup of kobject
is needed because memory may be allocated in kobject_init_and_add
without freeing.
And the place of cleanup_dev_kobject should use kobject_put to free the
memory associated with the kobject. As the section "Kobject removal" of
"Documentation/core-api/kobject.rst" says, kobject_del() just makes the
kobject "invisible", but it is not cleaned up. And no more cleanup will
do after cleanup_dev_kobject, so kobject_put is needed here.
Link: https://lkml.kernel.org/r/1625651306-10829-1-git-send-email-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/1625651306-10829-2-git-send-email-konishi.ryusuke@gmail.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Link: https://lkml.kernel.org/r/20210629022556.3985106-2-sunnanyong@huawei.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/nilfs2')
| -rw-r--r-- | fs/nilfs2/sysfs.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c index 68e8d61e28dd..d2d8ea89937a 100644 --- a/fs/nilfs2/sysfs.c +++ b/fs/nilfs2/sysfs.c @@ -986,7 +986,7 @@ int nilfs_sysfs_create_device_group(struct super_block *sb) err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL, "%s", sb->s_id); if (err) - goto free_dev_subgroups; + goto cleanup_dev_kobject; err = nilfs_sysfs_create_mounted_snapshots_group(nilfs); if (err) @@ -1023,9 +1023,7 @@ delete_mounted_snapshots_group: nilfs_sysfs_delete_mounted_snapshots_group(nilfs); cleanup_dev_kobject: - kobject_del(&nilfs->ns_dev_kobj); - -free_dev_subgroups: + kobject_put(&nilfs->ns_dev_kobj); kfree(nilfs->ns_dev_subgroups); failed_create_device_group: |