CVE-2023-54313: In the Linux kernel, the following vulnerability has been resolved: ovl: fix null pointer dereference in ovl_get_acl_rcu() Following process: P1 P2 path_openat…

PriorityP419low5.5

EPSS

0.17%

6.6th percentile

In the Linux kernel, the following vulnerability has been resolved: ovl: fix null pointer dereference in ovl_get_acl_rcu() Following process: P1 P2 path_openat link_path_walk may_lookup inode_permission(rcu) ovl_permission acl_permission_check check_acl get_cached_acl_rcu ovl_get_inode_acl realinode = ovl_inode_real(ovl_inode) drop_cache __dentry_kill(ovl_dentry) iput(ovl_inode) ovl_destroy_inode(ovl_inode) dput(oi->__upperdentry) dentry_kill(upperdentry) dentry_unlink_inode upperdentry->d_inode = NULL ovl_inode_upper upperdentry = ovl_i_dentry_upper(ovl_inode) d_inode(upperdentry) // returns NULL IS_POSIXACL(realinode) // NULL pointer dereference , will trigger an null pointer dereference at realinode: [ 205.472797] BUG: kernel NULL pointer dereference, address: 0000000000000028 [ 205.476701] CPU: 2 PID: 2713 Comm: ls Not tainted 6.3.0-12064-g2edfa098e750-dirty #1216 [ 205.478754] RIP: 0010:do_ovl_get_acl+0x5d/0x300 [ 205.489584] Call Trace: [ 205.489812] [ 205.490014] ovl_get_inode_acl+0x26/0x30 [ 205.490466] get_cached_acl_rcu+0x61/0xa0 [ 205.490908] generic_permission+0x1bf/0x4e0 [ 205.491447] ovl_permission+0x79/0x1b0 [ 205.491917] inode_permission+0x15e/0x2c0 [ 205.492425] link_path_walk+0x115/0x550 [ 205.493311] path_lookupat.isra.0+0xb2/0x200 [ 205.493803] filename_lookup+0xda/0x240 [ 205.495747] vfs_fstatat+0x7b/0xb0 Fetch a reproducer in [Link]. Use the helper ovl_i_path_realinode() to get realinode and then do non-nullptr checking.

Affected

12 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.1.52-1 (bookworm)	linux 6.1.52-1 (bookworm)
linux	linux	—	—
linux	linux	>= 332f606b32b6291a944c8cf23b91f53a6e676525 < d97481c7b2739a704848bb3c01f224dc71bdf78e	d97481c7b2739a704848bb3c01f224dc71bdf78e
linux	linux	>= 332f606b32b6291a944c8cf23b91f53a6e676525 < c4a5fb1ae5d3f02d3227afde2b9339994389463d	c4a5fb1ae5d3f02d3227afde2b9339994389463d
linux	linux	>= 332f606b32b6291a944c8cf23b91f53a6e676525 < d536af163c53ce9f9bcfe87d2e9946f06f1a7ea4	d536af163c53ce9f9bcfe87d2e9946f06f1a7ea4
linux	linux	>= 332f606b32b6291a944c8cf23b91f53a6e676525 < f4e19e595cc2e76a8a58413eb19d3d9c51328b53	f4e19e595cc2e76a8a58413eb19d3d9c51328b53
linux	linux_kernel	>= 0 < 6.1.52-1	6.1.52-1
linux	linux_kernel	>= 0 < 6.4.4-1	6.4.4-1
linux	linux_kernel	>= 0 < 6.4.4-1	6.4.4-1
linux	linux_kernel	>= 5.15.0 < 5.15.121	5.15.121
linux	linux_kernel	>= 5.16.0 < 6.1.40	6.1.40
linux	linux_kernel	>= 6.2.0 < 6.4.4	6.4.4

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