17be0ede8a
commit 1e022216dcd248326a5bb95609d12a6815bca4e2 upstream.
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:
1. 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().
2. 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:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| auth.c | ||
| budget.c | ||
| commit.c | ||
| compress.c | ||
| crypto.c | ||
| debug.c | ||
| debug.h | ||
| dir.c | ||
| file.c | ||
| find.c | ||
| gc.c | ||
| io.c | ||
| ioctl.c | ||
| journal.c | ||
| key.h | ||
| log.c | ||
| lprops.c | ||
| lpt.c | ||
| lpt_commit.c | ||
| master.c | ||
| misc.c | ||
| misc.h | ||
| orphan.c | ||
| recovery.c | ||
| replay.c | ||
| sb.c | ||
| scan.c | ||
| shrinker.c | ||
| super.c | ||
| sysfs.c | ||
| tnc.c | ||
| tnc_commit.c | ||
| tnc_misc.c | ||
| ubifs-media.h | ||
| ubifs.h | ||
| xattr.c | ||