diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-04 14:07:08 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-04 14:07:08 -0700 |
commit | 15a2bc4dbb9cfed1c661a657fcb10798150b7598 (patch) | |
tree | f9ca834dbdd2e6cf1d5a2cef5008f82c72b00261 /fs/binfmt_misc.c | |
parent | 9ff7258575d5fee011649d20cc56de720a395191 (diff) | |
parent | 3977e285ee89a94699255dbbf6eeea13889a1083 (diff) |
Merge branch 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull execve updates from Eric Biederman:
"Last cycle for the Nth time I ran into bugs and quality of
implementation issues related to exec that could not be easily be
fixed because of the way exec is implemented. So I have been digging
into exec and cleanup up what I can.
I don't think I have exec sorted out enough to fix the issues I
started with but I have made some headway this cycle with 4 sets of
changes.
- promised cleanups after introducing exec_update_mutex
- trivial cleanups for exec
- control flow simplifications
- remove the recomputation of bprm->cred
The net result is code that is a bit easier to understand and work
with and a decrease in the number of lines of code (if you don't count
the added tests)"
* 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (24 commits)
exec: Compute file based creds only once
exec: Add a per bprm->file version of per_clear
binfmt_elf_fdpic: fix execfd build regression
selftests/exec: Add binfmt_script regression test
exec: Remove recursion from search_binary_handler
exec: Generic execfd support
exec/binfmt_script: Don't modify bprm->buf and then return -ENOEXEC
exec: Move the call of prepare_binprm into search_binary_handler
exec: Allow load_misc_binary to call prepare_binprm unconditionally
exec: Convert security_bprm_set_creds into security_bprm_repopulate_creds
exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds
exec: Teach prepare_exec_creds how exec treats uids & gids
exec: Set the point of no return sooner
exec: Move handling of the point of no return to the top level
exec: Run sync_mm_rss before taking exec_update_mutex
exec: Fix spelling of search_binary_handler in a comment
exec: Move the comment from above de_thread to above unshare_sighand
exec: Rename flush_old_exec begin_new_exec
exec: Move most of setup_new_exec into flush_old_exec
exec: In setup_new_exec cache current in the local variable me
...
Diffstat (limited to 'fs/binfmt_misc.c')
-rw-r--r-- | fs/binfmt_misc.c | 69 |
1 files changed, 10 insertions, 59 deletions
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index cdb45829354d..bc5506619b7e 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -134,7 +134,6 @@ static int load_misc_binary(struct linux_binprm *bprm) Node *fmt; struct file *interp_file = NULL; int retval; - int fd_binary = -1; retval = -ENOEXEC; if (!enabled) @@ -160,51 +159,25 @@ static int load_misc_binary(struct linux_binprm *bprm) goto ret; } - if (fmt->flags & MISC_FMT_OPEN_BINARY) { + if (fmt->flags & MISC_FMT_OPEN_BINARY) + bprm->have_execfd = 1; - /* 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_flags(0); - if (fd_binary < 0) { - retval = fd_binary; - goto ret; - } - fd_install(fd_binary, bprm->file); - - /* if the binary is not readable than enforce mm->dumpable=0 - regardless of the interpreter's permissions */ - would_dump(bprm, bprm->file); - - allow_write_access(bprm->file); - bprm->file = NULL; - - /* mark the bprm that fd should be passed to interp */ - bprm->interp_flags |= BINPRM_FLAGS_EXECFD; - bprm->interp_data = fd_binary; - - } else { - allow_write_access(bprm->file); - fput(bprm->file); - bprm->file = NULL; - } /* make argv[1] be the path to the binary */ retval = copy_strings_kernel(1, &bprm->interp, bprm); if (retval < 0) - goto error; + goto ret; bprm->argc++; /* add the interp as argv[0] */ retval = copy_strings_kernel(1, &fmt->interpreter, bprm); if (retval < 0) - goto error; + goto ret; bprm->argc++; /* Update interp in case binfmt_script needs it. */ retval = bprm_change_interp(fmt->interpreter, bprm); if (retval < 0) - goto error; + goto ret; if (fmt->flags & MISC_FMT_OPEN_FILE) { interp_file = file_clone_open(fmt->interp_file); @@ -215,38 +188,16 @@ static int load_misc_binary(struct linux_binprm *bprm) } retval = PTR_ERR(interp_file); if (IS_ERR(interp_file)) - goto error; - - bprm->file = interp_file; - if (fmt->flags & MISC_FMT_CREDENTIALS) { - loff_t pos = 0; - - /* - * No need to call prepare_binprm(), it's already been - * done. bprm->buf is stale, update from interp_file. - */ - memset(bprm->buf, 0, BINPRM_BUF_SIZE); - retval = kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, - &pos); - } else - retval = prepare_binprm(bprm); - - if (retval < 0) - goto error; + goto ret; - retval = search_binary_handler(bprm); - if (retval < 0) - goto error; + bprm->interpreter = interp_file; + if (fmt->flags & MISC_FMT_CREDENTIALS) + bprm->execfd_creds = 1; + retval = 0; ret: dput(fmt->dentry); return retval; -error: - if (fd_binary > 0) - ksys_close(fd_binary); - bprm->interp_flags = 0; - bprm->interp_data = 0; - goto ret; } /* Command parsers */ |