diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2017-10-04 01:15:48 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-10-04 02:54:25 +0200 |
| commit | 83f918274e4b841d6fb817861ea0c896fba0c179 (patch) | |
| tree | 0dd2089b951b17b706cf1701149092cf56e75503 /fs | |
| parent | exec: binfmt_misc: don't nullify Node->dentry in kill_node() (diff) | |
| download | linux-83f918274e4b841d6fb817861ea0c896fba0c179.tar.xz linux-83f918274e4b841d6fb817861ea0c896fba0c179.zip | |
exec: binfmt_misc: shift filp_close(interp_file) from kill_node() to bm_evict_inode()
To ensure that load_misc_binary() can't use the partially destroyed
Node, see also the next patch.
The current logic looks wrong in any case, once we close interp_file it
doesn't make any sense to delay kfree(inode->i_private), this Node is no
longer valid. Even if the MISC_FMT_OPEN_FILE/interp_file checks were
not racy (they are), load_misc_binary() should not try to reopen
->interpreter if MISC_FMT_OPEN_FILE is set but ->interp_file is NULL.
And I can't understand why do we use filp_close(), not fput().
Link: http://lkml.kernel.org/r/20170922143644.GA17216@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ben Woodard <woodard@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jim Foraker <foraker1@llnl.gov>
Cc: <tdhooge@llnl.gov>
Cc: Travis Gummels <tgummels@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/binfmt_misc.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index 6451e7520e05..203598ccb40a 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -594,8 +594,13 @@ static struct inode *bm_get_inode(struct super_block *sb, int mode) static void bm_evict_inode(struct inode *inode) { + Node *e = inode->i_private; + + if ((e->flags & MISC_FMT_OPEN_FILE) && e->interp_file) + filp_close(e->interp_file, NULL); + clear_inode(inode); - kfree(inode->i_private); + kfree(e); } static void kill_node(Node *e) @@ -606,11 +611,6 @@ static void kill_node(Node *e) list_del_init(&e->list); write_unlock(&entries_lock); - if ((e->flags & MISC_FMT_OPEN_FILE) && e->interp_file) { - filp_close(e->interp_file, NULL); - e->interp_file = NULL; - } - dentry = e->dentry; drop_nlink(d_inode(dentry)); d_drop(dentry); |