| Message ID | 20221022115211.1969429-1-lizetao1@huawei.com |
|---|---|
| State | Accepted |
| Delegated to: | Richard Weinberger |
| Headers | show |
| Series | ubifs: Fix memory leak in alloc_wbufs() | expand |
在 2022/10/22 19:52, Li Zetao 写道: > kmemleak reported a sequence of memory leaks, and show them as following: > > unreferenced object 0xffff8881575f8400 (size 1024): > comm "mount", pid 19625, jiffies 4297119604 (age 20.383s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<ffffffff8176cecd>] __kmalloc+0x4d/0x150 > [<ffffffffa0406b2b>] ubifs_mount+0x307b/0x7170 [ubifs] > [<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0 > [<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230 > [<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0 > [<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270 > [<ffffffff83c14295>] do_syscall_64+0x35/0x80 > [<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > unreferenced object 0xffff8881798a6e00 (size 512): > comm "mount", pid 19677, jiffies 4297121912 (age 37.816s) > hex dump (first 32 bytes): > 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk > 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk > backtrace: > [<ffffffff8176cecd>] __kmalloc+0x4d/0x150 > [<ffffffffa0418342>] ubifs_wbuf_init+0x52/0x480 [ubifs] > [<ffffffffa0406ca5>] ubifs_mount+0x31f5/0x7170 [ubifs] > [<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0 > [<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230 > [<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0 > [<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270 > [<ffffffff83c14295>] do_syscall_64+0x35/0x80 > [<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > The problem is that the ubifs_wbuf_init() returns an error in the > loop which in the alloc_wbufs(), then the wbuf->buf and wbuf->inodes > that were successfully alloced before are not freed. > > Fix it by adding error hanging path in alloc_wbufs() which frees > the memory alloced before when ubifs_wbuf_init() returns an error. > > Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") > Signed-off-by: Li Zetao <lizetao1@huawei.com> > --- > fs/ubifs/super.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index d0c9a09988bc..32cb14759796 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -833,7 +833,7 @@ static int alloc_wbufs(struct ubifs_info *c) INIT_LIST_HEAD(&c->jheads[i].buds_list); err = ubifs_wbuf_init(c, &c->jheads[i].wbuf); if (err) - return err; + goto out_wbuf; c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback; c->jheads[i].wbuf.jhead = i; @@ -841,7 +841,7 @@ static int alloc_wbufs(struct ubifs_info *c) c->jheads[i].log_hash = ubifs_hash_get_desc(c); if (IS_ERR(c->jheads[i].log_hash)) { err = PTR_ERR(c->jheads[i].log_hash); - goto out; + goto out_log_hash; } } @@ -854,9 +854,18 @@ static int alloc_wbufs(struct ubifs_info *c) return 0; -out: - while (i--) +out_log_hash: + kfree(c->jheads[i].wbuf.buf); + kfree(c->jheads[i].wbuf.inodes); + +out_wbuf: + while (i--) { + kfree(c->jheads[i].wbuf.buf); + kfree(c->jheads[i].wbuf.inodes); kfree(c->jheads[i].log_hash); + } + kfree(c->jheads); + c->jheads = NULL; return err; }
kmemleak reported a sequence of memory leaks, and show them as following: unreferenced object 0xffff8881575f8400 (size 1024): comm "mount", pid 19625, jiffies 4297119604 (age 20.383s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8176cecd>] __kmalloc+0x4d/0x150 [<ffffffffa0406b2b>] ubifs_mount+0x307b/0x7170 [ubifs] [<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0 [<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230 [<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0 [<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270 [<ffffffff83c14295>] do_syscall_64+0x35/0x80 [<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 unreferenced object 0xffff8881798a6e00 (size 512): comm "mount", pid 19677, jiffies 4297121912 (age 37.816s) hex dump (first 32 bytes): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk backtrace: [<ffffffff8176cecd>] __kmalloc+0x4d/0x150 [<ffffffffa0418342>] ubifs_wbuf_init+0x52/0x480 [ubifs] [<ffffffffa0406ca5>] ubifs_mount+0x31f5/0x7170 [ubifs] [<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0 [<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230 [<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0 [<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270 [<ffffffff83c14295>] do_syscall_64+0x35/0x80 [<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 The problem is that the ubifs_wbuf_init() returns an error in the loop which in the alloc_wbufs(), then the wbuf->buf and wbuf->inodes that were successfully alloced before are not freed. Fix it by adding error hanging path in alloc_wbufs() which frees the memory alloced before when ubifs_wbuf_init() returns an error. Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Signed-off-by: Li Zetao <lizetao1@huawei.com> --- fs/ubifs/super.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)