Commit 76a67ec6 authored by J. Bruce Fields's avatar J. Bruce Fields

nfsd: nfsd should drop CAP_MKNOD for non-root

Since creating a device node is normally an operation requiring special
privilege, Igor Zhbanov points out that it is surprising (to say the
least) that a client can, for example, create a device node on a
filesystem exported with root_squash.

So, make sure CAP_MKNOD is among the capabilities dropped when an nfsd
thread handles a request from a non-root user.
Reported-by: default avatarIgor Zhbanov <izh1979@gmail.com>
Cc: stable@kernel.org
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 84f09f46
...@@ -393,8 +393,10 @@ struct cpu_vfs_cap_data { ...@@ -393,8 +393,10 @@ struct cpu_vfs_cap_data {
# define CAP_FULL_SET ((kernel_cap_t){{ ~0, ~0 }}) # define CAP_FULL_SET ((kernel_cap_t){{ ~0, ~0 }})
# define CAP_INIT_EFF_SET ((kernel_cap_t){{ ~CAP_TO_MASK(CAP_SETPCAP), ~0 }}) # define CAP_INIT_EFF_SET ((kernel_cap_t){{ ~CAP_TO_MASK(CAP_SETPCAP), ~0 }})
# define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0, CAP_FS_MASK_B1 } }) # define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0, CAP_FS_MASK_B1 } })
# define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0|CAP_TO_MASK(CAP_SYS_RESOURCE), \ # define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
CAP_FS_MASK_B1 } }) | CAP_TO_MASK(CAP_SYS_RESOURCE) \
| CAP_TO_MASK(CAP_MKNOD), \
CAP_FS_MASK_B1 } })
#endif /* _KERNEL_CAPABILITY_U32S != 2 */ #endif /* _KERNEL_CAPABILITY_U32S != 2 */
......
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