| From 76a67ec6fb79ff3570dcb5342142c16098299911 Mon Sep 17 00:00:00 2001 |
| From: J. Bruce Fields <bfields@citi.umich.edu> |
| Date: Mon, 16 Mar 2009 18:34:20 -0400 |
| Subject: nfsd: nfsd should drop CAP_MKNOD for non-root |
| |
| From: J. Bruce Fields <bfields@citi.umich.edu> |
| |
| commit 76a67ec6fb79ff3570dcb5342142c16098299911 upstream. |
| |
| 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 <izh1979@gmail.com> |
| Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| include/linux/capability.h | 6 ++++-- |
| 1 file changed, 4 insertions(+), 2 deletions(-) |
| |
| --- a/include/linux/capability.h |
| +++ b/include/linux/capability.h |
| @@ -382,8 +382,10 @@ typedef struct kernel_cap_struct { |
| # 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 */ |
| |
