From: J. Bruce Fields Date: Mon, 16 Mar 2009 22:34:20 +0000 (-0400) Subject: nfsd: nfsd should drop CAP_MKNOD for non-root X-Git-Tag: v2.6.29~22^2 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=76a67ec6fb79ff3570dcb5342142c16098299911 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: Igor Zhbanov Cc: stable@kernel.org Signed-off-by: J. Bruce Fields --- 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 */