diff options
| author | Miaoqian Lin <linmq006@gmail.com> | 2025-08-29 16:30:15 +0800 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2025-09-01 01:14:45 -0700 |
| commit | 5d5f08fd0cd970184376bee07d59f635c8403f63 (patch) | |
| tree | 138d5ac7436bf1539d4908e8aef18414d254ba90 | |
| parent | 038d61fd642278bab63ee8ef722c50d10ab01e8f (diff) | |
xtensa: simdisk: add input size check in proc_write_simdisk
A malicious user could pass an arbitrarily bad value
to memdup_user_nul(), potentially causing kernel crash.
This follows the same pattern as commit ee76746387f6
("netdevsim: prevent bad user input in nsim_dev_health_break_write()")
Fixes: b6c7e873daf7 ("xtensa: ISS: add host file-based simulated disk")
Fixes: 16e5c1fc3604 ("convert a bunch of open-coded instances of memdup_user_nul()")
Cc: stable@vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Message-Id: <20250829083015.1992751-1-linmq006@gmail.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
| -rw-r--r-- | arch/xtensa/platforms/iss/simdisk.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/xtensa/platforms/iss/simdisk.c b/arch/xtensa/platforms/iss/simdisk.c index 6ed009318d24..3cafc8feddee 100644 --- a/arch/xtensa/platforms/iss/simdisk.c +++ b/arch/xtensa/platforms/iss/simdisk.c @@ -231,10 +231,14 @@ static ssize_t proc_read_simdisk(struct file *file, char __user *buf, static ssize_t proc_write_simdisk(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - char *tmp = memdup_user_nul(buf, count); + char *tmp; struct simdisk *dev = pde_data(file_inode(file)); int err; + if (count == 0 || count > PAGE_SIZE) + return -EINVAL; + + tmp = memdup_user_nul(buf, count); if (IS_ERR(tmp)) return PTR_ERR(tmp); |