kernel.git/fs/jffs2/dir.c, branch linux-4.4.y

jffs2: fix UAF problem

2020-08-26T08:27:09Z

[ Upstream commit 798b7347e4f29553db4b996393caf12f5b233daf ] The log of UAF problem is listed below. BUG: KASAN: use-after-free in jffs2_rmdir+0xa4/0x1cc [jffs2] at addr c1f165fc Read of size 4 by task rm/8283 ============================================================================= BUG kmalloc-32 (Tainted: P B O ): kasan: bad access detected ----------------------------------------------------------------------------- INFO: Allocated in 0xbbbbbbbb age=3054364 cpu=0 pid=0 0xb0bba6ef jffs2_write_dirent+0x11c/0x9c8 [jffs2] __slab_alloc.isra.21.constprop.25+0x2c/0x44 __kmalloc+0x1dc/0x370 jffs2_write_dirent+0x11c/0x9c8 [jffs2] jffs2_do_unlink+0x328/0x5fc [jffs2] jffs2_rmdir+0x110/0x1cc [jffs2] vfs_rmdir+0x180/0x268 do_rmdir+0x2cc/0x300 ret_from_syscall+0x0/0x3c INFO: Freed in 0x205b age=3054364 cpu=0 pid=0 0x2e9173 jffs2_add_fd_to_list+0x138/0x1dc [jffs2] jffs2_add_fd_to_list+0x138/0x1dc [jffs2] jffs2_garbage_collect_dirent.isra.3+0x21c/0x288 [jffs2] jffs2_garbage_collect_live+0x16bc/0x1800 [jffs2] jffs2_garbage_collect_pass+0x678/0x11d4 [jffs2] jffs2_garbage_collect_thread+0x1e8/0x3b0 [jffs2] kthread+0x1a8/0x1b0 ret_from_kernel_thread+0x5c/0x64 Call Trace: [c17ddd20] [c02452d4] kasan_report.part.0+0x298/0x72c (unreliable) [c17ddda0] [d2509680] jffs2_rmdir+0xa4/0x1cc [jffs2] [c17dddd0] [c026da04] vfs_rmdir+0x180/0x268 [c17dde00] [c026f4e4] do_rmdir+0x2cc/0x300 [c17ddf40] [c001a658] ret_from_syscall+0x0/0x3c The root cause is that we don't get "jffs2_inode_info.sem" before we scan list "jffs2_inode_info.dents" in function jffs2_rmdir. This patch add codes to get "jffs2_inode_info.sem" before we scan "jffs2_inode_info.dents" to slove the UAF problem. Signed-off-by: Zhe Li Reviewed-by: Hou Tao Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

do d_instantiate/unlock_new_inode combinations safely

2018-05-30T05:48:52Z

commit 1e2e547a93a00ebc21582c06ca3c6cfea2a309ee upstream. For anything NFS-exported we do _not_ want to unlock new inode before it has grown an alias; original set of fixes got the ordering right, but missed the nasty complication in case of lockdep being enabled - unlock_new_inode() does lockdep_annotate_inode_mutex_key(inode) which can only be done before anyone gets a chance to touch ->i_mutex. Unfortunately, flipping the order and doing unlock_new_inode() before d_instantiate() opens a window when mkdir can race with open-by-fhandle on a guessed fhandle, leading to multiple aliases for a directory inode and all the breakage that follows from that. Correct solution: a new primitive (d_instantiate_new()) combining these two in the right order - lockdep annotate, then d_instantiate(), then the rest of unlock_new_inode(). All combinations of d_instantiate() with unlock_new_inode() should be converted to that. Cc: stable@kernel.org # 2.6.29 and later Tested-by: Mike Marshall Reviewed-by: Andreas Dilger Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

jffs2: reduce the breakage on recovery from halfway failed rename()

2016-03-16T15:42:58Z

commit f93812846f31381d35c04c6c577d724254355e7f upstream. d_instantiate(new_dentry, old_inode) is absolutely wrong thing to do - it will oops if new_dentry used to be positive, for starters. What we need is d_invalidate() the target and be done with that. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

jffs2: remove unnecessary new_valid_dev check

2015-09-28T23:19:16Z

As new_valid_dev always returns 1, so !new_valid_dev check is not needed, remove it. Signed-off-by: Yaowei Bai Signed-off-by: Brian Norris

jffs2: switch to simple_follow_link()

2015-05-11T02:18:23Z

Signed-off-by: Al Viro

VFS: normal filesystems (and lustre): d_inode() annotations

2015-04-15T19:06:57Z

that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells Signed-off-by: Al Viro

VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)

2015-02-22T16:38:41Z

Convert the following where appropriate: (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry). (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry). (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry). This is actually more complicated than it appears as some calls should be converted to d_can_lookup() instead. The difference is whether the directory in question is a real dir with a ->lookup op or whether it's a fake dir with a ->d_automount op. In some circumstances, we can subsume checks for dentry->d_inode not being NULL into this, provided we the code isn't in a filesystem that expects d_inode to be NULL if the dirent really *is* negative (ie. if we're going to use d_inode() rather than d_backing_inode() to get the inode pointer). Note that the dentry type field may be set to something other than DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS manages the fall-through from a negative dentry to a lower layer. In such a case, the dentry type of the negative union dentry is set to the same as the type of the lower dentry. However, if you know d_inode is not NULL at the call site, then you can use the d_is_xxx() functions even in a filesystem. There is one further complication: a 0,0 chardev dentry may be labelled DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE. Strictly, this was intended for special directory entry types that don't have attached inodes. The following perl+coccinelle script was used: use strict; my @callers; open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') || die "Can't grep for S_ISDIR and co. callers"; @callers = <$fd>; close($fd); unless (@callers) { print "No matches\n"; exit(0); } my @cocci = ( '@@', 'expression E;', '@@', '', '- S_ISLNK(E->d_inode->i_mode)', '+ d_is_symlink(E)', '', '@@', 'expression E;', '@@', '', '- S_ISDIR(E->d_inode->i_mode)', '+ d_is_dir(E)', '', '@@', 'expression E;', '@@', '', '- S_ISREG(E->d_inode->i_mode)', '+ d_is_reg(E)' ); my $coccifile = "tmp.sp.cocci"; open($fd, ">$coccifile") || die $coccifile; print($fd "$_\n") || die $coccifile foreach (@cocci); close($fd); foreach my $file (@callers) { chomp $file; print "Processing ", $file, "\n"; system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 || die "spatch failed"; } [AV: overlayfs parts skipped] Signed-off-by: David Howells Signed-off-by: Al Viro

jffs2: use generic posix ACL infrastructure

2014-01-26T04:58:20Z

Also don't bother to set up a .get_acl method for symlinks as we do not support access control (ACLs or even mode bits) for symlinks in Linux. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

[readdir] convert jffs2

2013-06-29T08:56:47Z

Signed-off-by: Al Viro

new helper: file_inode(file)

2013-02-23T04:31:31Z

Signed-off-by: Al Viro