diff options
Diffstat (limited to 'meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2023-52615.patch')
| -rw-r--r-- | meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2023-52615.patch | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2023-52615.patch b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2023-52615.patch new file mode 100644 index 000000000..9cb2c119c --- /dev/null +++ b/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/CVE-2023-52615.patch @@ -0,0 +1,120 @@ +From 26cc6d7006f922df6cc4389248032d955750b2a0 Mon Sep 17 00:00:00 2001 +From: Herbert Xu <herbert@gondor.apana.org.au> +Date: Sat, 2 Dec 2023 09:01:54 +0800 +Subject: hwrng: core - Fix page fault dead lock on mmap-ed hwrng + +commit 78aafb3884f6bc6636efcc1760c891c8500b9922 upstream. + +There is a dead-lock in the hwrng device read path. This triggers +when the user reads from /dev/hwrng into memory also mmap-ed from +/dev/hwrng. The resulting page fault triggers a recursive read +which then dead-locks. + +Fix this by using a stack buffer when calling copy_to_user. + +Reported-by: Edward Adam Davis <eadavis@qq.com> +Reported-by: syzbot+c52ab18308964d248092@syzkaller.appspotmail.com +Fixes: 9996508b3353 ("hwrng: core - Replace u32 in driver API with byte array") +Cc: <stable@vger.kernel.org> +Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + drivers/char/hw_random/core.c | 34 +++++++++++++++++++++------------- + 1 file changed, 21 insertions(+), 13 deletions(-) + +diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c +index cfb085de876b70..c3a2df67e0e997 100644 +--- a/drivers/char/hw_random/core.c ++++ b/drivers/char/hw_random/core.c +@@ -24,10 +24,13 @@ + #include <linux/random.h> + #include <linux/sched.h> + #include <linux/slab.h> ++#include <linux/string.h> + #include <linux/uaccess.h> + + #define RNG_MODULE_NAME "hw_random" + ++#define RNG_BUFFER_SIZE (SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES) ++ + static struct hwrng *current_rng; + /* the current rng has been explicitly chosen by user via sysfs */ + static int cur_rng_set_by_user; +@@ -59,7 +62,7 @@ static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, + + static size_t rng_buffer_size(void) + { +- return SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES; ++ return RNG_BUFFER_SIZE; + } + + static void add_early_randomness(struct hwrng *rng) +@@ -206,6 +209,7 @@ static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, + static ssize_t rng_dev_read(struct file *filp, char __user *buf, + size_t size, loff_t *offp) + { ++ u8 buffer[RNG_BUFFER_SIZE]; + ssize_t ret = 0; + int err = 0; + int bytes_read, len; +@@ -233,34 +237,37 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf, + if (bytes_read < 0) { + err = bytes_read; + goto out_unlock_reading; ++ } else if (bytes_read == 0 && ++ (filp->f_flags & O_NONBLOCK)) { ++ err = -EAGAIN; ++ goto out_unlock_reading; + } ++ + data_avail = bytes_read; + } + +- if (!data_avail) { +- if (filp->f_flags & O_NONBLOCK) { +- err = -EAGAIN; +- goto out_unlock_reading; +- } +- } else { +- len = data_avail; ++ len = data_avail; ++ if (len) { + if (len > size) + len = size; + + data_avail -= len; + +- if (copy_to_user(buf + ret, rng_buffer + data_avail, +- len)) { ++ memcpy(buffer, rng_buffer + data_avail, len); ++ } ++ mutex_unlock(&reading_mutex); ++ put_rng(rng); ++ ++ if (len) { ++ if (copy_to_user(buf + ret, buffer, len)) { + err = -EFAULT; +- goto out_unlock_reading; ++ goto out; + } + + size -= len; + ret += len; + } + +- mutex_unlock(&reading_mutex); +- put_rng(rng); + + if (need_resched()) + schedule_timeout_interruptible(1); +@@ -271,6 +278,7 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf, + } + } + out: ++ memzero_explicit(buffer, sizeof(buffer)); + return ret ? : err; + + out_unlock_reading: +-- +cgit 1.2.3-korg + |