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author | zhangyi (F) <yi.zhang@huawei.com> | 2019-11-06 17:43:52 +0800 |
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committer | Ben Hutchings <ben@decadent.org.uk> | 2019-12-19 15:59:03 +0000 |
commit | 58f675edecc46aec746cfea8407932a4459875dd (patch) | |
tree | 869c8b643280d1a464ad665fda6e508d9753ac4b /fs/dcache.c | |
parent | 79cf668f6a1336c35e2a7e9fb39cbd325d408484 (diff) | |
download | linux-stable-58f675edecc46aec746cfea8407932a4459875dd.tar.gz linux-stable-58f675edecc46aec746cfea8407932a4459875dd.tar.bz2 linux-stable-58f675edecc46aec746cfea8407932a4459875dd.zip |
fs/dcache: move security_d_instantiate() behind attaching dentry to inode
During backport 1e2e547a93a "do d_instantiate/unlock_new_inode
combinations safely", there was a error instantiating sequence of
attaching dentry to inode and calling security_d_instantiate().
Before commit ce23e640133 "->getxattr(): pass dentry and inode as
separate arguments" and b96809173e9 "security_d_instantiate(): move to
the point prior to attaching dentry to inode", security_d_instantiate()
should be called beind __d_instantiate(), otherwise it will trigger
below problem when CONFIG_SECURITY_SMACK on ext4 was enabled because
d_inode(dentry) used by ->getxattr() is NULL before __d_instantiate()
instantiate inode.
[ 31.858026] BUG: unable to handle kernel paging request at ffffffffffffff70
...
[ 31.882024] Call Trace:
[ 31.882378] [<ffffffffa347f75c>] ext4_xattr_get+0x8c/0x3e0
[ 31.883195] [<ffffffffa3489454>] ext4_xattr_security_get+0x24/0x40
[ 31.884086] [<ffffffffa336a56b>] generic_getxattr+0x5b/0x90
[ 31.884907] [<ffffffffa3700514>] smk_fetch+0xb4/0x150
[ 31.885634] [<ffffffffa3700772>] smack_d_instantiate+0x1c2/0x550
[ 31.886508] [<ffffffffa36f9a5a>] security_d_instantiate+0x3a/0x80
[ 31.887389] [<ffffffffa3353b26>] d_instantiate_new+0x36/0x130
[ 31.888223] [<ffffffffa342b1ef>] ext4_mkdir+0x4af/0x6a0
[ 31.888928] [<ffffffffa3343470>] vfs_mkdir+0x100/0x280
[ 31.889536] [<ffffffffa334b086>] SyS_mkdir+0xb6/0x170
[ 31.890255] [<ffffffffa307c855>] ? trace_do_page_fault+0x95/0x2b0
[ 31.891134] [<ffffffffa3c5e078>] entry_SYSCALL_64_fastpath+0x18/0x73
Cc: <stable@vger.kernel.org> # 3.16, 4.4
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs/dcache.c')
-rw-r--r-- | fs/dcache.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 6b0ef157a48b..9cd0e99812a5 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1685,7 +1685,6 @@ void d_instantiate_new(struct dentry *entry, struct inode *inode) BUG_ON(!hlist_unhashed(&entry->d_u.d_alias)); BUG_ON(!inode); lockdep_annotate_inode_mutex_key(inode); - security_d_instantiate(entry, inode); spin_lock(&inode->i_lock); __d_instantiate(entry, inode); WARN_ON(!(inode->i_state & I_NEW)); @@ -1693,6 +1692,7 @@ void d_instantiate_new(struct dentry *entry, struct inode *inode) smp_mb(); wake_up_bit(&inode->i_state, __I_NEW); spin_unlock(&inode->i_lock); + security_d_instantiate(entry, inode); } EXPORT_SYMBOL(d_instantiate_new); |