Messages in this thread Patch in this message | | | From | Yann Droneaud <> | Subject | [PATCH v4 3/7] binfmt_misc: use get_unused_fd_flags(0) instead of get_unused_fd() | Date | Wed, 30 Oct 2013 20:47:43 +0100 |
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Macro get_unused_fd() is used to allocate a file descriptor with default flags. Those default flags (0) can be "unsafe": O_CLOEXEC must be used by default to not leak file descriptor across exec().
Instead of macro get_unused_fd(), functions anon_inode_getfd() or get_unused_fd_flags() should be used with flags given by userspace. If not possible, flags should be set to O_CLOEXEC to provide userspace with a default safe behavor.
In a further patch, get_unused_fd() will be removed so that new code start using anon_inode_getfd() or get_unused_fd_flags() with correct flags.
This patch replaces calls to get_unused_fd() with equivalent call to get_unused_fd_flags(0) to preserve current behavor for existing code.
The hard coded flag value (0) should be reviewed on a per-subsystem basis, and, if possible, set to O_CLOEXEC.
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Link: http://lkml.kernel.org/r/cover.1383121137.git.ydroneaud@opteya.com --- fs/binfmt_misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index 1c740e1..052f6dc 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -138,7 +138,7 @@ static int load_misc_binary(struct linux_binprm *bprm) /* if the binary should be opened on behalf of the * interpreter than keep it open and assign descriptor * to it */ - fd_binary = get_unused_fd(); + fd_binary = get_unused_fd_flags(0); if (fd_binary < 0) { retval = fd_binary; goto _ret; -- 1.8.3.1
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