kernel/git/next/linux-next.git/drivers/block/zram, branch master

Merge https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-unstable into for-next

2026-09-14T07:56:18+00:00

Signed-off-by: David Hildenbrand (Arm)

zram: convert to SG-list zsmalloc object read API

2026-09-14T04:32:37+00:00

Patch series "zsmallc: remove old object read API". zram remains the only user of old zsmalloc object read API. This series removes the old API and converts zram to use the new SG-list based API. This patch (of 2): zram remains the last user of old zsmalloc object read API, that performed linearisation on the zsmalloc side. There is a new SG-list API, that has a bunch of benefits. Switch zram to SG-list zsmalloc object read API. Link: https://lore.kernel.org/20260907105739.1793316-1-senozhatsky@chromium.org Link: https://lore.kernel.org/20260907105739.1793316-2-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Signed-off-by: Andrew Morton Cc: Minchan Kim Cc: Nhat Pham

zram: remove unreachable kernel_read_file_from_path() return check

2026-09-14T04:31:54+00:00

Sashiko reported that: kernel_read_file_from_path() returns negative error for zero-sized files, so we cannot have "sz == 0" return, remove it and use a generic error message instead. Link: https://lore.kernel.org/20260901051335.2202390-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Signed-off-by: Andrew Morton Cc: Haoqin Huang

zram: fix idle age_sec underflow in idle_store()

2026-09-14T04:31:17+00:00

After commit 2e8ff2f51dde ("zram: use u32 for entry ac_time tracking"), idle_store() computes the idle cutoff as: cutoff = ktime_sub((u32)ktime_get_boottime_seconds(), age_sec); Because the left operand is cast to u32, when age_sec exceeds the current uptime the subtraction wraps modulo 2^32 and the huge result is zero-extended into the s64 cutoff. mark_idle() then marks every entry as idle instead of matching nothing. For instance, running echo 86400 > /sys/block/zramX/idle on a machine up for only two minutes marks all newly written pages idle and hands them to idle writeback and recompression. No slot can have been accessed before the system booted, so an age_sec that reaches back past uptime cannot match any slot. Return early in that case, without walking the table or taking any slot locks. Track the cutoff as time64_t rather than ktime_t. Both cutoff and ac_time are boot-time values in seconds, so a plain arithmetic comparison against ac_time in mark_idle() is correct and no ktime helpers are needed. Link: https://lore.kernel.org/20260828083149.45760-1-jiahao.kernel@gmail.com Fixes: 2e8ff2f51dde ("zram: use u32 for entry ac_time tracking") Signed-off-by: Hao Jia Signed-off-by: Andrew Morton Suggested-by: Sergey Senozhatsky Cc: Brian Geffon Cc: Jens Axboe Cc: Minchan Kim Cc:

treewide: refresh kmalloc_obj() conversions

2026-09-05T04:37:00+00:00

This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook

zram: fix slot lock bit position on big-endian 64-bit

2026-08-25T01:43:19+00:00

The slot lock is a bit operation on the whole __lock word, which flags and ac_time alias as two u32s. On little-endian the lock bit lands in the position ZRAM_ENTRY_LOCK reserves in flags, so the aliasing works out. On 64-bit big-endian it lands in ac_time instead: with ZRAM_TRACK_ENTRY_ACTIME enabled, storing the access time from mark_slot_accessed() or slot_free() wipes out the held lock bit, letting another CPU take the same slot lock; an access time value with that bit set makes the slot look locked forever. Shift the lock bit into the flags half of the word on big-endian 64-bit. Link: https://lore.kernel.org/20260810202241.2436603-1-devnexen@gmail.com Fixes: 2e8ff2f51dde ("zram: use u32 for entry ac_time tracking") Signed-off-by: David Carlier Reviewed-by: Sergey Senozhatsky Cc: Minchan Kim Cc: Signed-off-by: Andrew Morton

zram: switch to unsigned long indexing

2026-08-25T01:43:06+00:00

zram has always used "unsigned int" for (page) index calculations, which unnecessarily limited max zram disksize. Switch to "unsigned long" and permit much larger zram devices. Link: https://lore.kernel.org/20260806031640.536615-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Suggested-by: Andrew Morton Co-developed-by: Longlong Xia Cc: Minchan Kim Signed-off-by: Andrew Morton

zram: fix out-of-bounds access in read_block_state()

2026-08-25T01:43:05+00:00

read_block_state() calculates nr_pages before taking dev_lock. If the device is reset and reinitialized with a smaller disksize before lock acquisition, nr_pages still describes the old table. The subsequent loop can then call slot_lock() past the end of the newly allocated table. Read disksize after acquiring dev_lock and checking that the device is initialized. The read lock then keeps the table and its bound stable for the duration of the scan. Link: https://lore.kernel.org/20260804065919.3970386-3-xialonglong2025@163.com Fixes: c0265342bff4 ("zram: introduce zram memory tracking") Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Longlong Xia Reviewed-by: Sergey Senozhatsky Cc: Jens Axboe Cc: Minchan Kim Cc: Signed-off-by: Andrew Morton

zram: fix out-of-bounds access in writeback_store()

2026-08-25T01:43:05+00:00

Patch series "zram: fix stale scan bounds after reinitialization". Both writeback_store() and read_block_state() derive their table scan bounds from zram->disksize before acquiring dev_lock. If the device is reset and reinitialized with a smaller disksize between that read and lock acquisition, the bound can describe the old table while the scan operates on the new one. This can lead to out-of-bounds slot accesses. Move both bound calculations under dev_lock so each bound remains consistent with the table throughout its scan. Keep the fixes separate because the affected interfaces originate from different commits and can be backported independently. This patch (of 2): writeback_store() calculates the table scan bounds before taking dev_lock. A reset followed by reconfiguration with a smaller disksize can therefore replace zram->table while writeback_store() is waiting for the lock. Once it acquires the lock, it sees an initialized device but scans the new table using the old upper bound, resulting in an out-of-bounds access. Calculate the number of pages while holding dev_lock so the scan bound matches the table protected by the lock. Link: https://lore.kernel.org/20260804065919.3970386-1-xialonglong2025@163.com Link: https://lore.kernel.org/20260804065919.3970386-2-xialonglong2025@163.com Fixes: a939888ec38b ("zram: support idle/huge page writeback") Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Longlong Xia Reviewed-by: Sergey Senozhatsky Cc: Jens Axboe Cc: Minchan Kim Cc: Signed-off-by: Andrew Morton

zram: reset per-priority params when changing algorithm before init

2026-08-25T01:43:05+00:00

Parameters validated against one algorithm may be invalid for another (e.g. lz4 accepts level=65535 but zstd does not). Although algorithm changes are blocked after disksize is set, they are allowed before device initialization. Reset per-priority params on algorithm change so that stale parameters do not silently carry over. Link: https://lore.kernel.org/20260804093841.67920-6-haoqinhuang7@gmail.com Signed-off-by: Haoqin Huang Signed-off-by: Rongwei Wang Reviewed-by: Sergey Senozhatsky Tested-by: Sergey Senozhatsky Cc: David Sterba Cc: Jens Axboe Cc: Minchan Kim Cc: Nick Terrell Signed-off-by: Andrew Morton