On Wed, Oct 02, 2024 at 05:05:52PM +0200, Vegard Nossum wrote:
From: Zhihao Cheng chengzhihao1@huawei.com
[ Upstream commit 6379b44cdcd67f5f5d986b73953e99700591edfa ]
For error handling path in ubifs_symlink(), inode will be marked as bad first, then iput() is invoked. If inode->i_link is initialized by fscrypt_encrypt_symlink() in encryption scenario, inode->i_link won't be freed by callchain ubifs_free_inode -> fscrypt_free_inode in error handling path, because make_bad_inode() has changed 'inode->i_mode' as 'S_IFREG'. Following kmemleak is easy to be reproduced by injecting error in ubifs_jnl_update() when doing symlink in encryption scenario: unreferenced object 0xffff888103da3d98 (size 8): comm "ln", pid 1692, jiffies 4294914701 (age 12.045s) backtrace: kmemdup+0x32/0x70 __fscrypt_encrypt_symlink+0xed/0x1c0 ubifs_symlink+0x210/0x300 [ubifs] vfs_symlink+0x216/0x360 do_symlinkat+0x11a/0x190 do_syscall_64+0x3b/0xe0 There are two ways fixing it:
- Remove make_bad_inode() in error handling path. We can do that because ubifs_evict_inode() will do same processes for good symlink inode and bad symlink inode, for inode->i_nlink checking is before is_bad_inode().
- Free inode->i_link before marking inode bad.
Method 2 is picked, it has less influence, personally, I think.
Cc: stable@vger.kernel.org Fixes: 2c58d548f570 ("fscrypt: cache decrypted symlink target in ->i_link") Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Suggested-by: Eric Biggers ebiggers@kernel.org Reviewed-by: Eric Biggers ebiggers@google.com Signed-off-by: Richard Weinberger richard@nod.at (cherry picked from commit 6379b44cdcd67f5f5d986b73953e99700591edfa)
There isn't really a point to doing a cherry-pick -x if the information is already included at the top. I am surprised that you're on cherry-picking from the 6.10.y tree, though. Most stable patches are clean backports so it mostly doesn't matter either way.
regards, dan carpenter