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| author | Kyle Evans <kevans@FreeBSD.org> | 2020-08-31 15:07:15 +0000 |
|---|---|---|
| committer | Kyle Evans <kevans@FreeBSD.org> | 2020-08-31 15:07:15 +0000 |
| commit | 5dd47b52e59bbca60bda9388051d45ebbfc3305c (patch) | |
| tree | df90612c33d1cc5d18480f48c5b985c15cca5502 /sys/kern/uipc_shm.c | |
| parent | 641b7baa5b5d4eb76c79e69acba0a1c60a56f12d (diff) | |
| download | src-5dd47b52e59bbca60bda9388051d45ebbfc3305c.tar.gz src-5dd47b52e59bbca60bda9388051d45ebbfc3305c.zip | |
posixshm: fix setting of shm_flags
Noted in D24652, we currently set shmfd->shm_flags on every
shm_open()/shm_open2(). This wasn't properly thought out; one shouldn't be
able to specify incompatible flags on subsequent opens of non-anon shm.
Move setting of shm_flags explicitly to the two places shmfd are created, as
we do with seals, and validate when we're opening a pre-existing mapping
that we've either passed no flags or we've passed the exact same flags as
the first time.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D26242
Notes
Notes:
svn path=/head/; revision=364990
Diffstat (limited to 'sys/kern/uipc_shm.c')
| -rw-r--r-- | sys/kern/uipc_shm.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/sys/kern/uipc_shm.c b/sys/kern/uipc_shm.c index 796c2b08582a..74fc9b023b09 100644 --- a/sys/kern/uipc_shm.c +++ b/sys/kern/uipc_shm.c @@ -833,6 +833,7 @@ kern_shm_open2(struct thread *td, const char *userpath, int flags, mode_t mode, } shmfd = shm_alloc(td->td_ucred, cmode); shmfd->shm_seals = initial_seals; + shmfd->shm_flags = shmflags; } else { error = shm_copyin_path(td, userpath, &path); if (error != 0) { @@ -855,6 +856,7 @@ kern_shm_open2(struct thread *td, const char *userpath, int flags, mode_t mode, #endif shmfd = shm_alloc(td->td_ucred, cmode); shmfd->shm_seals = initial_seals; + shmfd->shm_flags = shmflags; shm_insert(path, fnv, shmfd); #ifdef MAC } @@ -898,6 +900,8 @@ kern_shm_open2(struct thread *td, const char *userpath, int flags, mode_t mode, else if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) error = EEXIST; + else if (shmflags != 0 && shmflags != shmfd->shm_flags) + error = EINVAL; else { #ifdef MAC error = mac_posixshm_check_open(td->td_ucred, @@ -947,7 +951,6 @@ kern_shm_open2(struct thread *td, const char *userpath, int flags, mode_t mode, } } - shmfd->shm_flags = shmflags; finit(fp, FFLAGS(flags & O_ACCMODE), DTYPE_SHM, shmfd, &shm_ops); td->td_retval[0] = fd; |