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authorMikulas Patocka <mpatocka@redhat.com>2017-11-14 15:59:54 +0100
committerDan Williams <dan.j.williams@intel.com>2017-11-15 08:48:42 +0100
commit9f586fff6574f6ecbf323f92d44ffaf0d96225fe (patch)
tree1192f55e600606c93d45424157efc5c973024a22 /drivers/dax/super.c
parentdax: fix PMD faults on zero-length files (diff)
downloadlinux-9f586fff6574f6ecbf323f92d44ffaf0d96225fe.tar.xz
linux-9f586fff6574f6ecbf323f92d44ffaf0d96225fe.zip
dax: fix general protection fault in dax_alloc_inode
Don't crash in case of allocation failure in dax_alloc_inode. syzkaller hit the following crash on e4880bc5dfb1 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access [..] RIP: 0010:dax_alloc_inode+0x3b/0x70 drivers/dax/super.c:348 Call Trace: alloc_inode+0x65/0x180 fs/inode.c:208 new_inode_pseudo+0x69/0x190 fs/inode.c:890 new_inode+0x1c/0x40 fs/inode.c:919 mount_pseudo_xattr+0x288/0x560 fs/libfs.c:261 mount_pseudo include/linux/fs.h:2137 [inline] dax_mount+0x2e/0x40 drivers/dax/super.c:388 mount_fs+0x66/0x2d0 fs/super.c:1223 Cc: <stable@vger.kernel.org> Fixes: 7b6be8444e0f ("dax: refactor dax-fs into a generic provider...") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dax/super.c')
-rw-r--r--drivers/dax/super.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 69329e3954ea..3ec804672601 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -341,6 +341,9 @@ static struct inode *dax_alloc_inode(struct super_block *sb)
struct inode *inode;
dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL);
+ if (!dax_dev)
+ return NULL;
+
inode = &dax_dev->inode;
inode->i_rdev = 0;
return inode;