diff options
| author | Zijun Hu <zijun.hu@oss.qualcomm.com> | 2025-07-14 18:34:17 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-11-24 12:29:29 +0300 |
| commit | 7d4ad49ba0c1922b5793afaa71223784c423bc7a (patch) | |
| tree | 36667e730a9af1162a9c7520671e912879afb4bb /drivers/char/misc.c | |
| parent | 4a61f3eb8913c9c31cba4f5d8e8edca24aaaa943 (diff) | |
| download | linux-7d4ad49ba0c1922b5793afaa71223784c423bc7a.tar.xz | |
char: misc: Does not request module for miscdevice with dynamic minor
[ Upstream commit 1ba0fb42aa6a5f072b1b8c0b0520b32ad4ef4b45 ]
misc_open() may request module for miscdevice with dynamic minor, which
is meaningless since:
- The dynamic minor allocated is unknown in advance without registering
miscdevice firstly.
- Macro MODULE_ALIAS_MISCDEV() is not applicable for dynamic minor.
Fix by only requesting module for miscdevice with fixed minor.
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-6-2ed949665bde@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/char/misc.c')
| -rw-r--r-- | drivers/char/misc.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 9ee78c76e866..6f9ce6b3cc5a 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -150,7 +150,8 @@ static int misc_open(struct inode *inode, struct file *file) break; } - if (!new_fops) { + /* Only request module for fixed minor code */ + if (!new_fops && minor < MISC_DYNAMIC_MINOR) { mutex_unlock(&misc_mtx); request_module("char-major-%d-%d", MISC_MAJOR, minor); mutex_lock(&misc_mtx); @@ -162,10 +163,11 @@ static int misc_open(struct inode *inode, struct file *file) new_fops = fops_get(iter->fops); break; } - if (!new_fops) - goto fail; } + if (!new_fops) + goto fail; + /* * Place the miscdevice in the file's * private_data so it can be used by the |