Hello! This is an experimental semi-automated report about issues detected by Coverity from a scan of next-20221110 as part of the linux-next scan project: https://scan.coverity.com/projects/linux-next-weekly-scan You're getting this email because you were associated with the identified lines of code (noted below) that were touched by commits: Wed Nov 9 20:33:48 2022 -0800 03e6c729aa64 ("zram: introduce recompress sysfs knob") Coverity reported the following: *** CID 1527270: (OVERRUN) drivers/block/zram/zram_drv.c:1727 in zram_recompress() 1721 zstrm = zcomp_stream_get(zram->comps[prio]); 1722 src = kmap_atomic(page); 1723 ret = zcomp_compress(zstrm, src, &comp_len_new); 1724 kunmap_atomic(src); 1725 1726 if (ret) { vvv CID 1527270: (OVERRUN) vvv Overrunning array "zram->comps" of 4 8-byte elements at element index 4 (byte offset 39) using index "prio" (which evaluates to 4). 1727 zcomp_stream_put(zram->comps[prio]); 1728 return ret; 1729 } 1730 1731 class_index_new = zs_lookup_class_index(zram->mem_pool, 1732 comp_len_new); drivers/block/zram/zram_drv.c:1786 in zram_recompress() 1780 handle_new = zs_malloc(zram->mem_pool, comp_len_new, 1781 __GFP_KSWAPD_RECLAIM | 1782 __GFP_NOWARN | 1783 __GFP_HIGHMEM | 1784 __GFP_MOVABLE); 1785 if (IS_ERR_VALUE(handle_new)) { vvv CID 1527270: (OVERRUN) vvv Overrunning array "zram->comps" of 4 8-byte elements at element index 4 (byte offset 39) using index "prio" (which evaluates to 4). 1786 zcomp_stream_put(zram->comps[prio]); 1787 return PTR_ERR((void *)handle_new); 1788 } 1789 1790 dst = zs_map_object(zram->mem_pool, handle_new, ZS_MM_WO); 1791 memcpy(dst, zstrm->buffer, comp_len_new); drivers/block/zram/zram_drv.c:1737 in zram_recompress() 1731 class_index_new = zs_lookup_class_index(zram->mem_pool, 1732 comp_len_new); 1733 1734 /* Continue until we make progress */ 1735 if (class_index_new >= class_index_old || 1736 (threshold && comp_len_new >= threshold)) { vvv CID 1527270: (OVERRUN) vvv Overrunning array "zram->comps" of 4 8-byte elements at element index 4 (byte offset 39) using index "prio" (which evaluates to 4). 1737 zcomp_stream_put(zram->comps[prio]); 1738 continue; 1739 } 1740 1741 /* Recompression was successful so break out */ 1742 break; drivers/block/zram/zram_drv.c:1721 in zram_recompress() 1715 * priority algorithm (or same algorithm). 1716 */ 1717 if (prio <= zram_get_priority(zram, index)) 1718 continue; 1719 1720 num_recomps++; vvv CID 1527270: (OVERRUN) vvv Overrunning array "zram->comps" of 4 8-byte elements at element index 4 (byte offset 39) using index "prio" (which evaluates to 4). 1721 zstrm = zcomp_stream_get(zram->comps[prio]); 1722 src = kmap_atomic(page); 1723 ret = zcomp_compress(zstrm, src, &comp_len_new); 1724 kunmap_atomic(src); 1725 1726 if (ret) { drivers/block/zram/zram_drv.c:1710 in zram_recompress() 1704 class_index_old = zs_lookup_class_index(zram->mem_pool, comp_len_old); 1705 /* 1706 * Iterate the secondary comp algorithms list (in order of priority) 1707 * and try to recompress the page. 1708 */ 1709 for (; prio < prio_max; prio++) { vvv CID 1527270: (OVERRUN) vvv Overrunning array "zram->comps" of 4 8-byte elements at element index 4 (byte offset 39) using index "prio" (which evaluates to 4). 1710 if (!zram->comps[prio]) 1711 continue; 1712 1713 /* 1714 * Skip if the object is already re-compressed with a higher 1715 * priority algorithm (or same algorithm). If this is a false positive, please let us know so we can mark it as such, or teach the Coverity rules to be smarter. If not, please make sure fixes get into linux-next. :) For patches fixing this, please include these lines (but double-check the "Fixes" first): Reported-by: coverity-bot <keescook+coverity-bot@xxxxxxxxxxxx> Addresses-Coverity-ID: 1527270 ("OVERRUN") Fixes: 03e6c729aa64 ("zram: introduce recompress sysfs knob") Thanks for your attention! -- Coverity-bot
