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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-03 20:46:22 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-03 20:46:22 +0200 |
| commit | 99f6cf61f175c1239ed8e86d4a1757c380da52d1 (patch) | |
| tree | 40a3325951af72ca293f3f21799f642a6e531fa6 | |
| parent | userfaultfd: simplify fault handling (diff) | |
| parent | mtd: properly check all write ioctls for permissions (diff) | |
| download | linux-99f6cf61f175c1239ed8e86d4a1757c380da52d1.tar.xz linux-99f6cf61f175c1239ed8e86d4a1757c380da52d1.zip | |
Merge branch 'mtd/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux
Pull mtd fix from Richard Weinberger.
* 'mtd/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
mtd: properly check all write ioctls for permissions
| -rw-r--r-- | drivers/mtd/mtdchar.c | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index c5935b2f9cd1..b40f46a43fc6 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -355,9 +355,6 @@ static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd, uint32_t retlen; int ret = 0; - if (!(file->f_mode & FMODE_WRITE)) - return -EPERM; - if (length > 4096) return -EINVAL; @@ -643,6 +640,48 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg) pr_debug("MTD_ioctl\n"); + /* + * Check the file mode to require "dangerous" commands to have write + * permissions. + */ + switch (cmd) { + /* "safe" commands */ + case MEMGETREGIONCOUNT: + case MEMGETREGIONINFO: + case MEMGETINFO: + case MEMREADOOB: + case MEMREADOOB64: + case MEMLOCK: + case MEMUNLOCK: + case MEMISLOCKED: + case MEMGETOOBSEL: + case MEMGETBADBLOCK: + case MEMSETBADBLOCK: + case OTPSELECT: + case OTPGETREGIONCOUNT: + case OTPGETREGIONINFO: + case OTPLOCK: + case ECCGETLAYOUT: + case ECCGETSTATS: + case MTDFILEMODE: + case BLKPG: + case BLKRRPART: + break; + + /* "dangerous" commands */ + case MEMERASE: + case MEMERASE64: + case MEMWRITEOOB: + case MEMWRITEOOB64: + case MEMWRITE: + if (!(file->f_mode & FMODE_WRITE)) + return -EPERM; + break; + + default: + return -ENOTTY; + } + switch (cmd) { case MEMGETREGIONCOUNT: if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int))) @@ -690,9 +729,6 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg) { struct erase_info *erase; - if(!(file->f_mode & FMODE_WRITE)) - return -EPERM; - erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL); if (!erase) ret = -ENOMEM; @@ -985,9 +1021,6 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg) ret = 0; break; } - - default: - ret = -ENOTTY; } return ret; @@ -1031,6 +1064,11 @@ static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd, struct mtd_oob_buf32 buf; struct mtd_oob_buf32 __user *buf_user = argp; + if (!(file->f_mode & FMODE_WRITE)) { + ret = -EPERM; + break; + } + if (copy_from_user(&buf, argp, sizeof(buf))) ret = -EFAULT; else |