4.4-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 3e351275655d3c84dc28abf170def9786db5176d ]
We could allocate less memory than intended because we do:
bfad->regdata = kzalloc(len << 2, GFP_KERNEL);
The shift can overflow leading to a crash. This is debugfs code so the impact is very small. I fixed the network version of this in March with commit 13e2d5187f6b ("bna: integer overflow bug in debugfs").
Fixes: ab2a9ba189e8 ("[SCSI] bfa: add debugfs support") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/scsi/bfa/bfad_debugfs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/scsi/bfa/bfad_debugfs.c +++ b/drivers/scsi/bfa/bfad_debugfs.c @@ -254,7 +254,8 @@ bfad_debugfs_write_regrd(struct file *fi struct bfad_s *bfad = port->bfad; struct bfa_s *bfa = &bfad->bfa; struct bfa_ioc_s *ioc = &bfa->ioc; - int addr, len, rc, i; + int addr, rc, i; + u32 len; u32 *regbuf; void __iomem *rb, *reg_addr; unsigned long flags; @@ -265,7 +266,7 @@ bfad_debugfs_write_regrd(struct file *fi return PTR_ERR(kern_buf);
rc = sscanf(kern_buf, "%x:%x", &addr, &len); - if (rc < 2) { + if (rc < 2 || len > (UINT_MAX >> 2)) { printk(KERN_INFO "bfad[%d]: %s failed to read user buf\n", bfad->inst_no, __func__);