diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-10-21 11:57:38 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-11-17 15:06:26 +0100 |
| commit | e2eb1b3c807ba475bcce89a6f0f21a62b14305cf (patch) | |
| tree | bfa81783e2a0b0ed7fa2cab8953e355fdac806b0 | |
| parent | 8b1d55e43cee631e142d46ee94c91ccd894341e9 (diff) | |
9p: fix slab cache name creation for real
commit a360f311f57a36e96d88fa8086b749159714dcd2 upstream.
This was attempted by using the dev_name in the slab cache name, but as
Omar Sandoval pointed out, that can be an arbitrary string, eg something
like "/dev/root". Which in turn trips verify_dirent_name(), which fails
if a filename contains a slash.
So just make it use a sequence counter, and make it an atomic_t to avoid
any possible races or locking issues.
Reported-and-tested-by: Omar Sandoval <osandov@fb.com>
Link: https://lore.kernel.org/all/ZxafcO8KWMlXaeWE@telecaster.dhcp.thefacebook.com/
Fixes: 79efebae4afc ("9p: Avoid creating multiple slab caches with the same name")
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/9p/client.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/9p/client.c b/net/9p/client.c index 03fb36d938c7..5f0b3fdc70e2 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -1003,6 +1003,7 @@ error: struct p9_client *p9_client_create(const char *dev_name, char *options) { int err; + static atomic_t seqno = ATOMIC_INIT(0); struct p9_client *clnt; char *client_id; char *cache_name; @@ -1058,7 +1059,8 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) if (err) goto close_trans; - cache_name = kasprintf(GFP_KERNEL, "9p-fcall-cache-%s", dev_name); + cache_name = kasprintf(GFP_KERNEL, + "9p-fcall-cache-%u", atomic_inc_return(&seqno)); if (!cache_name) { err = -ENOMEM; goto close_trans; |