CVE-2024-50151

In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix OOBs when building SMB2_IOCTL request

When using encryption, either enforced by the server or when using

'seal' mount option, the client will squash all compound request buffers

down for encryption into a single iov in smb2_set_next_command().

SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the

SMB2_IOCTL request in the first iov, and if the user passes an input

buffer that is greater than 328 bytes, smb2_set_next_command() will

end up writing off the end of @rqst->iov[0].iov_base as shown below:

mount.cifs //srv/share /mnt -o ...,seal

ln -s $(perl -e "print('a')for 1..1024") /mnt/link

BUG: KASAN: slab-out-of-bounds in

smb2_set_next_command.cold+0x1d6/0x24c [cifs]

Write of size 4116 at addr ffff8881148fcab8 by task ln/859

CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS

1.16.3-2.fc40 04/01/2014

Call Trace:

<TASK>

dump_stack_lvl+0x5d/0x80

? smb2_set_next_command.cold+0x1d6/0x24c [cifs]

print_report+0x156/0x4d9

? smb2_set_next_command.cold+0x1d6/0x24c [cifs]

? __virt_addr_valid+0x145/0x310

? __phys_addr+0x46/0x90

? smb2_set_next_command.cold+0x1d6/0x24c [cifs]

kasan_report+0xda/0x110

? smb2_set_next_command.cold+0x1d6/0x24c [cifs]

kasan_check_range+0x10f/0x1f0

__asan_memcpy+0x3c/0x60

smb2_set_next_command.cold+0x1d6/0x24c [cifs]

smb2_compound_op+0x238c/0x3840 [cifs]

? kasan_save_track+0x14/0x30

? kasan_save_free_info+0x3b/0x70

? vfs_symlink+0x1a1/0x2c0

? do_symlinkat+0x108/0x1c0

? __pfx_smb2_compound_op+0x10/0x10 [cifs]

? kmem_cache_free+0x118/0x3e0

? cifs_get_writable_path+0xeb/0x1a0 [cifs]

smb2_get_reparse_inode+0x423/0x540 [cifs]

? __pfx_smb2_get_reparse_inode+0x10/0x10 [cifs]

? rcu_is_watching+0x20/0x50

? __kmalloc_noprof+0x37c/0x480

? smb2_create_reparse_symlink+0x257/0x490 [cifs]

? smb2_create_reparse_symlink+0x38f/0x490 [cifs]

smb2_create_reparse_symlink+0x38f/0x490 [cifs]

? __pfx_smb2_create_reparse_symlink+0x10/0x10 [cifs]

? find_held_lock+0x8a/0xa0

? hlock_class+0x32/0xb0

? __build_path_from_dentry_optional_prefix+0x19d/0x2e0 [cifs]

cifs_symlink+0x24f/0x960 [cifs]

? __pfx_make_vfsuid+0x10/0x10

? __pfx_cifs_symlink+0x10/0x10 [cifs]

? make_vfsgid+0x6b/0xc0

? generic_permission+0x96/0x2d0

vfs_symlink+0x1a1/0x2c0

do_symlinkat+0x108/0x1c0

? __pfx_do_symlinkat+0x10/0x10

? strncpy_from_user+0xaa/0x160

__x64_sys_symlinkat+0xb9/0xf0

do_syscall_64+0xbb/0x1d0

entry_SYSCALL_64_after_hwframe+0x77/0x7f

RIP: 0033:0x7f08d75c13bb