projects/linux·commit 76a67ec6

nfsd: nfsd should drop CAP_MKNOD for non-root

76a67ec6 · J. Bruce Fields <[email protected]> · 2009-03-16 18:34:20 -04:00

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: Igor Zhbanov <[email protected]>
Cc: [email protected]
Signed-off-by: J. Bruce Fields <[email protected]>
Commit
76a67ec6fb79ff3570dcb5342142c16098299911
Parents
84f09f46

Changes

1 files changed · +4 −2

FileStatusAddDelContent
include/linux/capability.hmodified+4−2View file

include/linux/capability.h

View file
diff --git a/include/linux/capability.h b/include/linux/capability.h
index 1b98725..4864a43 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -393,8 +393,10 @@ struct cpu_vfs_cap_data {
# 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_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), \
- CAP_FS_MASK_B1 } })
+# define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
+ | CAP_TO_MASK(CAP_SYS_RESOURCE) \
+ | CAP_TO_MASK(CAP_MKNOD), \
+ CAP_FS_MASK_B1 } })
#endif /* _KERNEL_CAPABILITY_U32S != 2 */