Since linux-next-20240613 firefox-esr crashes after several minutes of browsing giving the following error messages in dmesg: [ T2343] BUG: Bad rss-counter state mm:00000000babe0c39 type:MM_ANONPAGES val:86 [ T4063] show_signal_msg: 16 callbacks suppressed [ T4063] Isolated Web Co[4063]: segfault at 396d1686c000 ip 0000396d1686c000 sp 00007ffd767b30a8 error 14 likely on CPU 7 (core 3, socket 0) [ T4063] Code: Unable to access opcode bytes at 0x396d1686bfd6. [ T4211] BUG: Bad rss-counter state mm:00000000cd9fc541 type:MM_ANONPAGES val:817 [ T3798] BUG: Bad rss-counter state mm:00000000432d87c2 type:MM_ANONPAGES val:181 [ T5548] BUG: Bad rss-counter state mm:00000000034aa27a type:MM_ANONPAGES val:242 [ T3823] BUG: Bad rss-counter state mm:0000000099734197 type:MM_ANONPAGES val:137 [ T1] BUG: Bad rss-counter state mm:000000005e5e2f2f type:MM_ANONPAGES val:28 (these are the error messages of several crashes and the error seems to affect other processes, too (T1)) The crash can be provoked to appear in ~1min by opening large numbers of tabs in firefox-esr (by holding pressing ctrl+t for some time). With this I bisected the error to commit "1c29a32ce65f mm/mmap: use split munmap calls for MAP_FIXED" and reverting this commit in linux-next-20240613 fixes the issue for me. Bert Karwatzki PS. Please CC me when answering, I'm not subscribed to the lists.