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| author | Shivank Garg <shivankg@amd.com> | 2025-06-20 07:03:30 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-17 18:32:10 +0200 |
| commit | 66d29d757c968d2bee9124816da5d718eb352959 (patch) | |
| tree | e356de2e66324414e7370764f53dda2415b083db /mm | |
| parent | ac6b093e88d99dcd480ff0860ada104546e200d0 (diff) | |
| download | linux-66d29d757c968d2bee9124816da5d718eb352959.tar.gz linux-66d29d757c968d2bee9124816da5d718eb352959.tar.bz2 linux-66d29d757c968d2bee9124816da5d718eb352959.zip | |
fs: export anon_inode_make_secure_inode() and fix secretmem LSM bypass
[ Upstream commit cbe4134ea4bc493239786220bd69cb8a13493190 ]
Export anon_inode_make_secure_inode() to allow KVM guest_memfd to create
anonymous inodes with proper security context. This replaces the current
pattern of calling alloc_anon_inode() followed by
inode_init_security_anon() for creating security context manually.
This change also fixes a security regression in secretmem where the
S_PRIVATE flag was not cleared after alloc_anon_inode(), causing
LSM/SELinux checks to be bypassed for secretmem file descriptors.
As guest_memfd currently resides in the KVM module, we need to export this
symbol for use outside the core kernel. In the future, guest_memfd might be
moved to core-mm, at which point the symbols no longer would have to be
exported. When/if that happens is still unclear.
Fixes: 2bfe15c52612 ("mm: create security context for memfd_secret inodes")
Suggested-by: David Hildenbrand <david@redhat.com>
Suggested-by: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://lore.kernel.org/20250620070328.803704-3-shivankg@amd.com
Acked-by: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/secretmem.c | 11 |
1 files changed, 1 insertions, 10 deletions
diff --git a/mm/secretmem.c b/mm/secretmem.c index c6006d765bbd..18954eae995f 100644 --- a/mm/secretmem.c +++ b/mm/secretmem.c @@ -193,19 +193,10 @@ static struct file *secretmem_file_create(unsigned long flags) struct file *file = ERR_PTR(-ENOMEM); struct inode *inode; const char *anon_name = "[secretmem]"; - const struct qstr qname = QSTR_INIT(anon_name, strlen(anon_name)); - int err; - inode = alloc_anon_inode(secretmem_mnt->mnt_sb); + inode = anon_inode_make_secure_inode(secretmem_mnt->mnt_sb, anon_name, NULL); if (IS_ERR(inode)) return ERR_CAST(inode); - - err = security_inode_init_security_anon(inode, &qname, NULL); - if (err) { - file = ERR_PTR(err); - goto err_free_inode; - } - file = alloc_file_pseudo(inode, secretmem_mnt, "secretmem", O_RDWR, &secretmem_fops); if (IS_ERR(file)) |