From 09cefcddf38db51f7b3168a17572d138279ab01c Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 20 Jun 2019 18:49:36 +0200 Subject: [PATCH] 4.9-stable patches added patches: abort-file_remove_privs-for-non-reg.-files.patch --- ...file_remove_privs-for-non-reg.-files.patch | 51 +++++++++++++++++++ queue-4.9/series | 1 + 2 files changed, 52 insertions(+) create mode 100644 queue-4.9/abort-file_remove_privs-for-non-reg.-files.patch diff --git a/queue-4.9/abort-file_remove_privs-for-non-reg.-files.patch b/queue-4.9/abort-file_remove_privs-for-non-reg.-files.patch new file mode 100644 index 00000000000..569f4d5bd3a --- /dev/null +++ b/queue-4.9/abort-file_remove_privs-for-non-reg.-files.patch @@ -0,0 +1,51 @@ +From f69e749a49353d96af1a293f56b5b56de59c668a Mon Sep 17 00:00:00 2001 +From: Alexander Lochmann +Date: Fri, 14 Dec 2018 11:55:52 +0100 +Subject: Abort file_remove_privs() for non-reg. files + +From: Alexander Lochmann + +commit f69e749a49353d96af1a293f56b5b56de59c668a upstream. + +file_remove_privs() might be called for non-regular files, e.g. +blkdev inode. There is no reason to do its job on things +like blkdev inodes, pipes, or cdevs. Hence, abort if +file does not refer to a regular inode. + +AV: more to the point, for devices there might be any number of +inodes refering to given device. Which one to strip the permissions +from, even if that made any sense in the first place? All of them +will be observed with contents modified, after all. + +Found by LockDoc (Alexander Lochmann, Horst Schirmeier and Olaf +Spinczyk) + +Reviewed-by: Jan Kara +Signed-off-by: Alexander Lochmann +Signed-off-by: Horst Schirmeier +Signed-off-by: Al Viro +Cc: Zubin Mithra +Signed-off-by: Greg Kroah-Hartman + +--- + fs/inode.c | 9 +++++++-- + 1 file changed, 7 insertions(+), 2 deletions(-) + +--- a/fs/inode.c ++++ b/fs/inode.c +@@ -1804,8 +1804,13 @@ int file_remove_privs(struct file *file) + int kill; + int error = 0; + +- /* Fast path for nothing security related */ +- if (IS_NOSEC(inode)) ++ /* ++ * Fast path for nothing security related. ++ * As well for non-regular files, e.g. blkdev inodes. ++ * For example, blkdev_write_iter() might get here ++ * trying to remove privs which it is not allowed to. ++ */ ++ if (IS_NOSEC(inode) || !S_ISREG(inode->i_mode)) + return 0; + + kill = dentry_needs_remove_privs(dentry); diff --git a/queue-4.9/series b/queue-4.9/series index df40140be8d..140b24d38ba 100644 --- a/queue-4.9/series +++ b/queue-4.9/series @@ -114,3 +114,4 @@ scsi-libcxgbi-add-a-check-for-null-pointer-in-cxgbi_.patch scsi-smartpqi-properly-set-both-the-dma-mask-and-the.patch scsi-libsas-delete-sas-port-if-expander-discover-fai.patch mlxsw-spectrum-prevent-force-of-56g.patch +abort-file_remove_privs-for-non-reg.-files.patch -- 2.47.3