From e203db293863fa15b4b1917d4398fb5bd63c4e88 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Salva=20Peir=C3=B3?= Date: Thu, 23 Jul 2015 14:26:19 +0200 Subject: [PATCH] iommu/omap: Fix debug_read_tlb() to use seq_printf() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The debug_read_tlb() uses the sprintf() functions directly on the buffer allocated by buf = kmalloc(count), without taking into account the size of the buffer, with the consequence corrupting the heap, depending on the count requested by the user. The patch fixes the issue replacing sprintf() by seq_printf(). Signed-off-by: Salva Peiró Signed-off-by: Joerg Roedel --- drivers/iommu/omap-iommu-debug.c | 48 ++++++++++---------------------- 1 file changed, 14 insertions(+), 34 deletions(-) diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c index e9f116f18531..0717aa96ce39 100644 --- a/drivers/iommu/omap-iommu-debug.c +++ b/drivers/iommu/omap-iommu-debug.c @@ -133,26 +133,18 @@ __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num) } static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr, - char *buf) + struct seq_file *s) { - char *p = buf; - - /* FIXME: Need more detail analysis of cam/ram */ - p += sprintf(p, "%08x %08x %01x\n", cr->cam, cr->ram, - (cr->cam & MMU_CAM_P) ? 1 : 0); - - return p - buf; + return seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram, + (cr->cam & MMU_CAM_P) ? 1 : 0); } -static size_t omap_dump_tlb_entries(struct omap_iommu *obj, char *buf, - ssize_t bytes) +static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s) { int i, num; struct cr_regs *cr; - char *p = buf; - num = bytes / sizeof(*cr); - num = min(obj->nr_tlb_entries, num); + num = obj->nr_tlb_entries; cr = kcalloc(num, sizeof(*cr), GFP_KERNEL); if (!cr) @@ -160,40 +152,28 @@ static size_t omap_dump_tlb_entries(struct omap_iommu *obj, char *buf, num = __dump_tlb_entries(obj, cr, num); for (i = 0; i < num; i++) - p += iotlb_dump_cr(obj, cr + i, p); + iotlb_dump_cr(obj, cr + i, s); kfree(cr); - return p - buf; + return 0; } -static ssize_t debug_read_tlb(struct file *file, char __user *userbuf, - size_t count, loff_t *ppos) +static int debug_read_tlb(struct seq_file *s, void *data) { - struct omap_iommu *obj = file->private_data; - char *p, *buf; - ssize_t bytes, rest; + struct omap_iommu *obj = s->private; if (is_omap_iommu_detached(obj)) return -EPERM; - buf = kmalloc(count, GFP_KERNEL); - if (!buf) - return -ENOMEM; - p = buf; - mutex_lock(&iommu_debug_lock); - p += sprintf(p, "%8s %8s\n", "cam:", "ram:"); - p += sprintf(p, "-----------------------------------------\n"); - rest = count - (p - buf); - p += omap_dump_tlb_entries(obj, p, rest); - - bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf); + seq_printf(s, "%8s %8s\n", "cam:", "ram:"); + seq_puts(s, "-----------------------------------------\n"); + omap_dump_tlb_entries(obj, s); mutex_unlock(&iommu_debug_lock); - kfree(buf); - return bytes; + return 0; } static void dump_ioptable(struct seq_file *s) @@ -268,7 +248,7 @@ static int debug_read_pagetable(struct seq_file *s, void *data) } DEBUG_FOPS_RO(regs); -DEBUG_FOPS_RO(tlb); +DEBUG_SEQ_FOPS_RO(tlb); DEBUG_SEQ_FOPS_RO(pagetable); #define __DEBUG_ADD_FILE(attr, mode) \ -- 2.39.2