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author | David S. Miller <davem@davemloft.net> | 2019-08-06 18:44:57 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2019-08-06 18:44:57 -0700 |
commit | 13dfb3fa494361ea9a5950f27c9cd8b06d28c04f (patch) | |
tree | 1bf30874f57c6c6b21160a10282191fcd0868055 /fs/open.c | |
parent | Merge branch '40GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue (diff) | |
parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net (diff) | |
download | linux-dev-13dfb3fa494361ea9a5950f27c9cd8b06d28c04f.tar.xz linux-dev-13dfb3fa494361ea9a5950f27c9cd8b06d28c04f.zip |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Just minor overlapping changes in the conflicts here.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'fs/open.c')
-rw-r--r-- | fs/open.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/fs/open.c b/fs/open.c index b5b80469b93d..a59abe3c669a 100644 --- a/fs/open.c +++ b/fs/open.c @@ -374,6 +374,25 @@ long do_faccessat(int dfd, const char __user *filename, int mode) override_cred->cap_permitted; } + /* + * The new set of credentials can *only* be used in + * task-synchronous circumstances, and does not need + * RCU freeing, unless somebody then takes a separate + * reference to it. + * + * NOTE! This is _only_ true because this credential + * is used purely for override_creds() that installs + * it as the subjective cred. Other threads will be + * accessing ->real_cred, not the subjective cred. + * + * If somebody _does_ make a copy of this (using the + * 'get_current_cred()' function), that will clear the + * non_rcu field, because now that other user may be + * expecting RCU freeing. But normal thread-synchronous + * cred accesses will keep things non-RCY. + */ + override_cred->non_rcu = 1; + old_cred = override_creds(override_cred); retry: res = user_path_at(dfd, filename, lookup_flags, &path); |