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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-04-24 14:06:41 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-04-24 14:06:41 -0700 |
| commit | 97adb49f052e70455c3529509885f8aa3b40c370 (patch) | |
| tree | c646f53d8bad336e9a7b2e8bed527b2217334cab | |
| parent | e2eff52ce512ec725f9f1daf975c45a499be1e1e (diff) | |
| parent | 43b450632676fb60e9faeddff285d9fac94a4f58 (diff) | |
| download | linux-stable-97adb49f052e70455c3529509885f8aa3b40c370.tar.gz | |
Merge tag 'v6.4/vfs.open' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs open fixlet from Christian Brauner:
"EINVAL ist keinmal: This contains the changes to make O_DIRECTORY when
specified together with O_CREAT an invalid request.
The wider background is that a regression report about the behavior of
O_DIRECTORY | O_CREAT was sent to fsdevel about a behavior that was
changed multiple years and LTS releases earlier during v5.7
development.
This has also been covered in
https://lwn.net/Articles/926782/
which provides an excellent summary of the discussion"
* tag 'v6.4/vfs.open' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
open: return EINVAL for O_DIRECTORY | O_CREAT
| -rw-r--r-- | fs/open.c | 18 | ||||
| -rw-r--r-- | include/uapi/asm-generic/fcntl.h | 1 | ||||
| -rw-r--r-- | tools/include/uapi/asm-generic/fcntl.h | 1 |
3 files changed, 13 insertions, 7 deletions
diff --git a/fs/open.c b/fs/open.c index 4401a73d4032..4478adcc4f3a 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1196,13 +1196,21 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op) } /* - * In order to ensure programs get explicit errors when trying to use - * O_TMPFILE on old kernels, O_TMPFILE is implemented such that it - * looks like (O_DIRECTORY|O_RDWR & ~O_CREAT) to old kernels. But we - * have to require userspace to explicitly set it. + * Block bugs where O_DIRECTORY | O_CREAT created regular files. + * Note, that blocking O_DIRECTORY | O_CREAT here also protects + * O_TMPFILE below which requires O_DIRECTORY being raised. */ + if ((flags & (O_DIRECTORY | O_CREAT)) == (O_DIRECTORY | O_CREAT)) + return -EINVAL; + + /* Now handle the creative implementation of O_TMPFILE. */ if (flags & __O_TMPFILE) { - if ((flags & O_TMPFILE_MASK) != O_TMPFILE) + /* + * In order to ensure programs get explicit errors when trying + * to use O_TMPFILE on old kernels we enforce that O_DIRECTORY + * is raised alongside __O_TMPFILE. + */ + if (!(flags & O_DIRECTORY)) return -EINVAL; if (!(acc_mode & MAY_WRITE)) return -EINVAL; diff --git a/include/uapi/asm-generic/fcntl.h b/include/uapi/asm-generic/fcntl.h index 1ecdb911add8..80f37a0d40d7 100644 --- a/include/uapi/asm-generic/fcntl.h +++ b/include/uapi/asm-generic/fcntl.h @@ -91,7 +91,6 @@ /* a horrid kludge trying to make sure that this will fail on old kernels */ #define O_TMPFILE (__O_TMPFILE | O_DIRECTORY) -#define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT) #ifndef O_NDELAY #define O_NDELAY O_NONBLOCK diff --git a/tools/include/uapi/asm-generic/fcntl.h b/tools/include/uapi/asm-generic/fcntl.h index b02c8e0f4057..1c7a0f6632c0 100644 --- a/tools/include/uapi/asm-generic/fcntl.h +++ b/tools/include/uapi/asm-generic/fcntl.h @@ -91,7 +91,6 @@ /* a horrid kludge trying to make sure that this will fail on old kernels */ #define O_TMPFILE (__O_TMPFILE | O_DIRECTORY) -#define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT) #ifndef O_NDELAY #define O_NDELAY O_NONBLOCK |