From 2feb55f89096b22e2de066e411a3263647211987 Mon Sep 17 00:00:00 2001 From: Wouter van Kesteren Date: Tue, 16 Feb 2016 22:20:59 +0100 Subject: [PATCH 1/4] fs: allow no_seek_end_llseek to actually seek The user-visible impact of the issue is for example that without this patch sensors-detect breaks when trying to seek in /dev/cpu/0/cpuid. '~0ULL' is a 'unsigned long long' that when converted to a loff_t, which is signed, gets turned into -1. later in vfs_setpos we have 'if (offset > maxsize)', which makes it always return EINVAL. Fixes: b25472f9b961 ("new helpers: no_seek_end_llseek{,_size}()") Signed-off-by: Wouter van Kesteren Reviewed-by: Andreas Dilger Signed-off-by: Al Viro --- fs/read_write.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/read_write.c b/fs/read_write.c index 324ec271cc4e..0c8782aa3d71 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -17,6 +17,7 @@ #include #include #include +#include #include "internal.h" #include @@ -183,7 +184,7 @@ loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence) switch (whence) { case SEEK_SET: case SEEK_CUR: return generic_file_llseek_size(file, offset, whence, - ~0ULL, 0); + OFFSET_MAX, 0); default: return -EINVAL; } From 0e9a7da51b028aee7a72c95096c99fe5ea2a01f0 Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Thu, 4 Feb 2016 02:56:30 +0100 Subject: [PATCH 2/4] xattr handlers: plug a lock leak in simple_xattr_list The code could leak xattrs->lock on error. Problem introduced with 786534b92f3ce68f4 "tmpfs: listxattr should include POSIX ACL xattrs". Signed-off-by: Mateusz Guzik Signed-off-by: Al Viro --- fs/xattr.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/xattr.c b/fs/xattr.c index 07d0e47f6a7f..4861322e28e8 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -940,7 +940,7 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, bool trusted = capable(CAP_SYS_ADMIN); struct simple_xattr *xattr; ssize_t remaining_size = size; - int err; + int err = 0; #ifdef CONFIG_FS_POSIX_ACL if (inode->i_acl) { @@ -965,11 +965,11 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, err = xattr_list_one(&buffer, &remaining_size, xattr->name); if (err) - return err; + break; } spin_unlock(&xattrs->lock); - return size - remaining_size; + return err ? err : size - remaining_size; } /* From 0bacbe528e26422e424d110ebda4ec68ea0fd5eb Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 2 Feb 2016 02:28:05 +0000 Subject: [PATCH 3/4] affs_do_readpage_ofs(): just use kmap_atomic() around memcpy() It forgets kunmap() on a failure exit, but there's really no point keeping the page kmapped at all - after all, what we are doing is a bunch of memcpy() into the parts of page, so kmap_atomic()/kunmap_atomic() just around those memcpy() is enough. Spotted-by: Insu Yun Signed-off-by: Al Viro --- fs/affs/file.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/affs/file.c b/fs/affs/file.c index 0548c53f41d5..22fc7c802d69 100644 --- a/fs/affs/file.c +++ b/fs/affs/file.c @@ -511,8 +511,6 @@ affs_do_readpage_ofs(struct page *page, unsigned to) pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino, page->index, to); BUG_ON(to > PAGE_CACHE_SIZE); - kmap(page); - data = page_address(page); bsize = AFFS_SB(sb)->s_data_blksize; tmp = page->index << PAGE_CACHE_SHIFT; bidx = tmp / bsize; @@ -524,14 +522,15 @@ affs_do_readpage_ofs(struct page *page, unsigned to) return PTR_ERR(bh); tmp = min(bsize - boff, to - pos); BUG_ON(pos + tmp > to || tmp > bsize); + data = kmap_atomic(page); memcpy(data + pos, AFFS_DATA(bh) + boff, tmp); + kunmap_atomic(data); affs_brelse(bh); bidx++; pos += tmp; boff = 0; } flush_dcache_page(page); - kunmap(page); return 0; } From 7ae8fd0351f912b075149a1e03a017be8b903b9a Mon Sep 17 00:00:00 2001 From: Maxim Patlasov Date: Tue, 16 Feb 2016 11:45:33 -0800 Subject: [PATCH 4/4] fs/pnode.c: treat zero mnt_group_id-s as unequal propagate_one(m) calculates "type" argument for copy_tree() like this: > if (m->mnt_group_id == last_dest->mnt_group_id) { > type = CL_MAKE_SHARED; > } else { > type = CL_SLAVE; > if (IS_MNT_SHARED(m)) > type |= CL_MAKE_SHARED; > } The "type" argument then governs clone_mnt() behavior with respect to flags and mnt_master of new mount. When we iterate through a slave group, it is possible that both current "m" and "last_dest" are not shared (although, both are slaves, i.e. have non-NULL mnt_master-s). Then the comparison above erroneously makes new mount shared and sets its mnt_master to last_source->mnt_master. The patch fixes the problem by handling zero mnt_group_id-s as though they are unequal. The similar problem exists in the implementation of "else" clause above when we have to ascend upward in the master/slave tree by calling: > last_source = last_source->mnt_master; > last_dest = last_source->mnt_parent; proper number of times. The last step is governed by "n->mnt_group_id != last_dest->mnt_group_id" condition that may lie if both are zero. The patch fixes this case in the same way as the former one. [AV: don't open-code an obvious helper...] Signed-off-by: Maxim Patlasov Signed-off-by: Al Viro --- fs/pnode.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/pnode.c b/fs/pnode.c index 6367e1e435c6..c524fdddc7fb 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -202,6 +202,11 @@ static struct mount *last_dest, *last_source, *dest_master; static struct mountpoint *mp; static struct hlist_head *list; +static inline bool peers(struct mount *m1, struct mount *m2) +{ + return m1->mnt_group_id == m2->mnt_group_id && m1->mnt_group_id; +} + static int propagate_one(struct mount *m) { struct mount *child; @@ -212,7 +217,7 @@ static int propagate_one(struct mount *m) /* skip if mountpoint isn't covered by it */ if (!is_subdir(mp->m_dentry, m->mnt.mnt_root)) return 0; - if (m->mnt_group_id == last_dest->mnt_group_id) { + if (peers(m, last_dest)) { type = CL_MAKE_SHARED; } else { struct mount *n, *p; @@ -223,7 +228,7 @@ static int propagate_one(struct mount *m) last_source = last_source->mnt_master; last_dest = last_source->mnt_parent; } - if (n->mnt_group_id != last_dest->mnt_group_id) { + if (!peers(n, last_dest)) { last_source = last_source->mnt_master; last_dest = last_source->mnt_parent; }