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authorLinus Torvalds <torvalds@linux-foundation.org>2019-01-02 16:35:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-02 16:35:23 -0800
commite6b92572808467f35fd159d47c45b650de29e722 (patch)
tree5fbd2e6279539c4f3eeeca0d6a69779bdbd0d6a4 /kernel
parente45428a436765fcd154d461a2739b5640916dc00 (diff)
parent260f71eff493a844531629854c0935fa8de4fa2c (diff)
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Merge tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client updates from Anna Schumaker: "Stable bugfixes: - xprtrdma: Yet another double DMA-unmap # v4.20 Features: - Allow some /proc/sys/sunrpc entries without CONFIG_SUNRPC_DEBUG - Per-xprt rdma receive workqueues - Drop support for FMR memory registration - Make port= mount option optional for RDMA mounts Other bugfixes and cleanups: - Remove unused nfs4_xdev_fs_type declaration - Fix comments for behavior that has changed - Remove generic RPC credentials by switching to 'struct cred' - Fix crossing mountpoints with different auth flavors - Various xprtrdma fixes from testing and auditing the close code - Fixes for disconnect issues when using xprtrdma with krb5 - Clean up and improve xprtrdma trace points - Fix NFS v4.2 async copy reboot recovery" * tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (63 commits) sunrpc: convert to DEFINE_SHOW_ATTRIBUTE sunrpc: Add xprt after nfs4_test_session_trunk() sunrpc: convert unnecessary GFP_ATOMIC to GFP_NOFS sunrpc: handle ENOMEM in rpcb_getport_async NFS: remove unnecessary test for IS_ERR(cred) xprtrdma: Prevent leak of rpcrdma_rep objects NFSv4.2 fix async copy reboot recovery xprtrdma: Don't leak freed MRs xprtrdma: Add documenting comment for rpcrdma_buffer_destroy xprtrdma: Replace outdated comment for rpcrdma_ep_post xprtrdma: Update comments in frwr_op_send SUNRPC: Fix some kernel doc complaints SUNRPC: Simplify defining common RPC trace events NFS: Fix NFSv4 symbolic trace point output xprtrdma: Trace mapping, alloc, and dereg failures xprtrdma: Add trace points for calls to transport switch methods xprtrdma: Relocate the xprtrdma_mr_map trace points xprtrdma: Clean up of xprtrdma chunk trace points xprtrdma: Remove unused fields from rpcrdma_ia xprtrdma: Cull dprintk() call sites ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cred.c58
1 files changed, 57 insertions, 1 deletions
diff --git a/kernel/cred.c b/kernel/cred.c
index ecf03657e71c..21f4a97085b4 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -19,6 +19,7 @@
#include <linux/security.h>
#include <linux/binfmts.h>
#include <linux/cn_proc.h>
+#include <linux/uidgid.h>
#if 0
#define kdebug(FMT, ...) \
@@ -194,11 +195,12 @@ const struct cred *get_task_cred(struct task_struct *task)
do {
cred = __task_cred((task));
BUG_ON(!cred);
- } while (!atomic_inc_not_zero(&((struct cred *)cred)->usage));
+ } while (!get_cred_rcu(cred));
rcu_read_unlock();
return cred;
}
+EXPORT_SYMBOL(get_task_cred);
/*
* Allocate blank credentials, such that the credentials can be filled in at a
@@ -564,6 +566,60 @@ void revert_creds(const struct cred *old)
}
EXPORT_SYMBOL(revert_creds);
+/**
+ * cred_fscmp - Compare two credentials with respect to filesystem access.
+ * @a: The first credential
+ * @b: The second credential
+ *
+ * cred_cmp() will return zero if both credentials have the same
+ * fsuid, fsgid, and supplementary groups. That is, if they will both
+ * provide the same access to files based on mode/uid/gid.
+ * If the credentials are different, then either -1 or 1 will
+ * be returned depending on whether @a comes before or after @b
+ * respectively in an arbitrary, but stable, ordering of credentials.
+ *
+ * Return: -1, 0, or 1 depending on comparison
+ */
+int cred_fscmp(const struct cred *a, const struct cred *b)
+{
+ struct group_info *ga, *gb;
+ int g;
+
+ if (a == b)
+ return 0;
+ if (uid_lt(a->fsuid, b->fsuid))
+ return -1;
+ if (uid_gt(a->fsuid, b->fsuid))
+ return 1;
+
+ if (gid_lt(a->fsgid, b->fsgid))
+ return -1;
+ if (gid_gt(a->fsgid, b->fsgid))
+ return 1;
+
+ ga = a->group_info;
+ gb = b->group_info;
+ if (ga == gb)
+ return 0;
+ if (ga == NULL)
+ return -1;
+ if (gb == NULL)
+ return 1;
+ if (ga->ngroups < gb->ngroups)
+ return -1;
+ if (ga->ngroups > gb->ngroups)
+ return 1;
+
+ for (g = 0; g < ga->ngroups; g++) {
+ if (gid_lt(ga->gid[g], gb->gid[g]))
+ return -1;
+ if (gid_gt(ga->gid[g], gb->gid[g]))
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(cred_fscmp);
+
/*
* initialise the credentials stuff
*/