https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 https://jira.whamcloud.com/browse/LU-17517 Lustre <p>One of our clients just gave us this:</p> <p>[  201.440391] UBSAN: shift-out-of-bounds in /var/lib/dkms/lustre-client-modules/2.15.4-hpc2n0.2/build/lustre/lov/lov_request.c:230:23<br/> [  201.452215] shift exponent 65 is too large for 64-bit type 'long long unsigned int'<br/> [  201.460108] ================================================================================<br/> [  201.468547] ================================================================================<br/> [  201.476985] UBSAN: shift-out-of-bounds in /var/lib/dkms/lustre-client-modules/2.15.4-hpc2n0.2/build/lustre/lov/lov_request.c:231:23<br/> [  201.488810] shift exponent 65 is too large for 64-bit type 'long long unsigned int'<br/> [  201.496944] ================================================================================<br/> [  201.505378] ================================================================================<br/> [  201.513819] UBSAN: shift-out-of-bounds in /var/lib/dkms/lustre-client-modules/2.15.4-hpc2n0.2/build/lustre/lov/lov_request.c:232:23<br/> [  201.525642] shift exponent 65 is too large for 64-bit type 'long long unsigned int'</p> <p> </p> LU-17517

shift exponent 65 is too large for 64-bit type in lov_request.c

Bug Minor Open Unresolved WC Triage Åke Sandgren Thu, 8 Feb 2024 15:31:37 +0000 Fri, 9 Feb 2024 01:07:35 +0000 Lustre 2.15.4 0 2 <p><tt>Seems like in `lov_update_statfs()`, the logic</tt></p> <blockquote><p><tt> 200                         for (shift = 0; shift &lt;= 64; ++shift) {</tt><br/> <tt> 201                                 if (tmp &amp; 1) {</tt><br/> <tt> 202                                         if (quit)</tt><br/> <tt> 203                                                 break;</tt><br/> <tt> 204                                         quit = 1;</tt><br/> <tt> 205                                         shift = 0;</tt><br/>   206                                                              }<br/> <tt> 207                                 tmp &gt;&gt;= 1;</tt><br/>   208                                              }</p></blockquote> <p><tt>is wrong. If we finish the loop without breaking, `shift` will be 65. I think if `shift` is 64, that's also undefined behavior. It'd have to be capped at 63.</tt></p> Development Rank 1|i04auv: Rank (Obsolete) 9223372036854775807 Severity