| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 14/92] gfs2: Dont leave s_fs_info pointing to freed memory in init_sbd | Date | Thu, 29 Nov 2018 15:11:43 +0100 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Andrew Price <anprice@redhat.com>
commit 4c62bd9cea7bcf10292f7e4c57a2bca332942697 upstream.
When alloc_percpu() fails, sdp gets freed but sb->s_fs_info still points to the same address. Move the assignment after that error check so that s_fs_info can only point to a valid sdp or NULL, which is checked for later in the error path, in gfs2_kill_super().
Reported-by: syzbot+dcb8b3587445007f5808@syzkaller.appspotmail.com Signed-off-by: Andrew Price <anprice@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/gfs2/ops_fstype.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -71,13 +71,13 @@ static struct gfs2_sbd *init_sbd(struct if (!sdp) return NULL; - sb->s_fs_info = sdp; sdp->sd_vfs = sb; sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats); if (!sdp->sd_lkstats) { kfree(sdp); return NULL; } + sb->s_fs_info = sdp; set_bit(SDF_NOJOURNALID, &sdp->sd_flags); gfs2_tune_init(&sdp->sd_tune);
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