hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAOH1I

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The function cifs_writedata_alloc() first allocates pages and then executes cifs_writedata_direct_alloc(). If the subsequent allocation of wdata fails, the previously allocated pages are not released, leading to a memory leak:

hex dump (first 8 bytes): 00 00 00 00 00 00 00 00 ........ backtrace: [<00000000c2b9cca5>] cifs_write_from_iter.isra.0+0x103/0x730 [<0000000069a4b2e6>] cifs_user_writev+0x138/0x280 [<00000000bfdbeacd>] __vfs_write+0x12b/0x190 [<00000000460567cf>] vfs_write+0xac/0x1a0 [<00000000f92e5dfc>] ksys_write+0x43/0xb0 [<0000000094ddd57e>] do_syscall_64+0x63/0x220 [<0000000055ce26ff>] entry_SYSCALL_64_after_hwframe+0x5c/0xc1 [<00000000359223fa>] 0xffffffffffffffff

This issue can be avoided by promptly using kvfree.

Fixes: 8e7360f67e75 ("CIFS: Add support for direct pages in wdata") Signed-off-by: Zizhi Wo wozizhi@huawei.com --- fs/cifs/cifssmb.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index cb70f0c6aa1b..7950c906e7b3 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -2129,6 +2129,8 @@ cifs_writedata_direct_alloc(struct page **pages, work_func_t complete) INIT_LIST_HEAD(&wdata->list); init_completion(&wdata->done); INIT_WORK(&wdata->work, complete); + } else { + kvfree(pages); } return wdata; }