From: Greg Kroah-Hartman Date: Sat, 2 May 2020 06:18:01 +0000 (+0200) Subject: 4.4-stable patches X-Git-Tag: v5.4.37~4 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=92826ed30613608645bc1918086d55318198fb68;p=thirdparty%2Fkernel%2Fstable-queue.git 4.4-stable patches added patches: propagate_one-mnt_set_mountpoint-needs-mount_lock.patch --- diff --git a/queue-4.4/propagate_one-mnt_set_mountpoint-needs-mount_lock.patch b/queue-4.4/propagate_one-mnt_set_mountpoint-needs-mount_lock.patch new file mode 100644 index 00000000000..02c6e3f34d8 --- /dev/null +++ b/queue-4.4/propagate_one-mnt_set_mountpoint-needs-mount_lock.patch @@ -0,0 +1,46 @@ +From b0d3869ce9eeacbb1bbd541909beeef4126426d5 Mon Sep 17 00:00:00 2001 +From: Al Viro +Date: Mon, 27 Apr 2020 10:26:22 -0400 +Subject: propagate_one(): mnt_set_mountpoint() needs mount_lock + +From: Al Viro + +commit b0d3869ce9eeacbb1bbd541909beeef4126426d5 upstream. + +... to protect the modification of mp->m_count done by it. Most of +the places that modify that thing also have namespace_lock held, +but not all of them can do so, so we really need mount_lock here. +Kudos to Piotr Krysiuk , who'd spotted a related +bug in pivot_root(2) (fixed unnoticed in 5.3); search for other +similar turds has caught out this one. + +Cc: stable@kernel.org +Signed-off-by: Al Viro +Signed-off-by: Piotr Krysiuk +Signed-off-by: Greg Kroah-Hartman + +--- + fs/pnode.c | 9 ++++----- + 1 file changed, 4 insertions(+), 5 deletions(-) + +--- a/fs/pnode.c ++++ b/fs/pnode.c +@@ -268,14 +268,13 @@ static int propagate_one(struct mount *m + if (IS_ERR(child)) + return PTR_ERR(child); + child->mnt.mnt_flags &= ~MNT_LOCKED; ++ read_seqlock_excl(&mount_lock); + mnt_set_mountpoint(m, mp, child); ++ if (m->mnt_master != dest_master) ++ SET_MNT_MARK(m->mnt_master); ++ read_sequnlock_excl(&mount_lock); + last_dest = m; + last_source = child; +- if (m->mnt_master != dest_master) { +- read_seqlock_excl(&mount_lock); +- SET_MNT_MARK(m->mnt_master); +- read_sequnlock_excl(&mount_lock); +- } + hlist_add_head(&child->mnt_hash, list); + return count_mounts(m->mnt_ns, child); + } diff --git a/queue-4.4/series b/queue-4.4/series index a68792e77a3..3f231561565 100644 --- a/queue-4.4/series +++ b/queue-4.4/series @@ -67,3 +67,4 @@ ext4-protect-journal-inode-s-blocks-using-block_validity.patch ext4-don-t-perform-block-validity-checks-on-the-journal-inode.patch ext4-fix-block-validity-checks-for-journal-inodes-using-indirect-blocks.patch ext4-unsigned-int-compared-against-zero.patch +propagate_one-mnt_set_mountpoint-needs-mount_lock.patch