Good catch. Tentatively merged into cifs-2.6.git for-next pending testing.
On Sat, Oct 22, 2022 at 1:32 AM Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx> wrote:
>
> There is a memory leak when writedata alloc failed:
>
> unreferenced object 0xffff888192364000 (size 8192):
> comm "sync", pid 22839, jiffies 4297313967 (age 60.230s)
> 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:
> [<0000000027de0814>] __kmalloc+0x4d/0x150
> [<00000000b21e81ab>] cifs_writepages+0x35f/0x14a0
> [<0000000076f7d20e>] do_writepages+0x10a/0x360
> [<00000000d6a36edc>] filemap_fdatawrite_wbc+0x95/0xc0
> [<000000005751a323>] __filemap_fdatawrite_range+0xa7/0xe0
> [<0000000088afb0ca>] file_write_and_wait_range+0x66/0xb0
> [<0000000063dbc443>] cifs_strict_fsync+0x80/0x5f0
> [<00000000c4624754>] __x64_sys_fsync+0x40/0x70
> [<000000002c0dc744>] do_syscall_64+0x35/0x80
> [<0000000052f46bee>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
>
> cifs_writepages+0x35f/0x14a0 is:
> kmalloc_array at include/linux/slab.h:628
> (inlined by) kcalloc at include/linux/slab.h:659
> (inlined by) cifs_writedata_alloc at fs/cifs/file.c:2438
> (inlined by) wdata_alloc_and_fillpages at fs/cifs/file.c:2527
> (inlined by) cifs_writepages at fs/cifs/file.c:2705
>
> If writedata alloc failed in cifs_writedata_alloc(), the pages array
> should be freed.
>
> Fixes: 8e7360f67e75 ("CIFS: Add support for direct pages in wdata")
> Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx>
> ---
> fs/cifs/file.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 87be0223a57a..cd9698209930 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -2434,12 +2434,16 @@ cifs_writev_complete(struct work_struct *work)
> struct cifs_writedata *
> cifs_writedata_alloc(unsigned int nr_pages, work_func_t complete)
> {
> + struct cifs_writedata *writedata = NULL;
> struct page **pages =
> kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
> - if (pages)
> - return cifs_writedata_direct_alloc(pages, complete);
> + if (pages) {
> + writedata = cifs_writedata_direct_alloc(pages, complete);
> + if (!writedata)
> + kvfree(pages);
> + }
>
> - return NULL;
> + return writedata;
> }
>
> struct cifs_writedata *
> --
> 2.31.1
>
--
Thanks,
Steve
