Author: jah Date: Fri May 20 03:03:04 2016 New Revision: 300258 URL: https://svnweb.freebsd.org/changeset/base/300258
Log: iic_rdwr_data->nmsgs is uint32_t, so limit the allowable number of messages to prevent memory exhaustion and short allocations on 32-bit systems. Since iicrdwr is intended to be a workalike of a Linux i2c-dev call, use the same limit of 42 that Linux uses. Also check the return value of copyin(9) to prevent unnecessary allocation in the failure case. Submitted by: ngie Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D5155 Modified: head/sys/dev/iicbus/iic.c head/sys/dev/iicbus/iic.h Modified: head/sys/dev/iicbus/iic.c ============================================================================== --- head/sys/dev/iicbus/iic.c Fri May 20 01:41:47 2016 (r300257) +++ head/sys/dev/iicbus/iic.c Fri May 20 03:03:04 2016 (r300258) @@ -300,9 +300,16 @@ iicrdwr(struct iic_cdevpriv *priv, struc parent = device_get_parent(iicdev); error = 0; + if (d->nmsgs > IIC_RDRW_MAX_MSGS) + return (EINVAL); + buf = malloc(sizeof(*d->msgs) * d->nmsgs, M_IIC, M_WAITOK); error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs); + if (error != 0) { + free(buf, M_IIC); + return (error); + } /* Alloc kernel buffers for userland data, copyin write data */ usrbufs = malloc(sizeof(void *) * d->nmsgs, M_IIC, M_WAITOK | M_ZERO); @@ -318,6 +325,8 @@ iicrdwr(struct iic_cdevpriv *priv, struc m->buf = NULL; if (error != 0) continue; + + /* m->len is uint16_t, so allocation size is capped at 64K. */ m->buf = malloc(m->len, M_IIC, M_WAITOK); if (!(m->flags & IIC_M_RD)) error = copyin(usrbufs[i], m->buf, m->len); Modified: head/sys/dev/iicbus/iic.h ============================================================================== --- head/sys/dev/iicbus/iic.h Fri May 20 01:41:47 2016 (r300257) +++ head/sys/dev/iicbus/iic.h Fri May 20 03:03:04 2016 (r300258) @@ -56,6 +56,8 @@ struct iic_rdwr_data { uint32_t nmsgs; }; +#define IIC_RDRW_MAX_MSGS 42 + #define I2CSTART _IOW('i', 1, struct iiccmd) /* start condition */ #define I2CSTOP _IO('i', 2) /* stop condition */ #define I2CRSTCARD _IOW('i', 3, struct iiccmd) /* reset the card */ _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
