* [PATCH] cxl/pci: Fix out-of-bounds read of the RAS Header Log
@ 2026-06-05 4:16 Richard Cheng
2026-06-05 15:30 ` Dave Jiang
0 siblings, 1 reply; 6+ messages in thread
From: Richard Cheng @ 2026-06-05 4:16 UTC (permalink / raw)
To: dave, jic23, dave.jiang, alison.schofield, vishal.l.verma,
ira.weiny, djbw
Cc: linux-cxl, linux-kernel, newtonl, kristinc, kaihengf, kobak,
smadhavan, vaslot, Richard Cheng
The CXL RAS Header Log is 64 bytes, but CXL_HEADERLOG_SIZE is SZ_512,
which is 512 bytes, not 512 bits, so the kernel treats it as 8x times
bigger.
header_log_copy() reads 448 bytes of MMIO past the register, and
cxl_*_aer_uncorrectable_error() tracepoints memcpy 512 bytes from the
64-byte header log. On the CPER path the source is a heap object, so the
copy runs 448 bytes past it and leaks kernel memory into a trace record
that userspace can read:
"""
[ 297.704020] BUG: KASAN: slab-out-of-bounds in trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0
[ 297.704032] Read of size 512 at addr ffff0000dd6ee118 by task bash/3078
[ 297.704038] CPU: 116 UID: 0 PID: 3078 Comm: bash Not tainted 7.1.0-rc6+ #1 PREEMPT(full)
[ 297.704041] Hardware name: , BIOS buildbrain-gcid-sbios-45660680 Wed May 27 08:27:58 AM UTC 2026
[ 297.704042] Call trace:
[ 297.704043] show_stack+0x24/0x50 (C)
[ 297.704049] dump_stack_lvl+0x80/0x140
[ 297.704053] print_report+0x100/0x630
[ 297.704057] kasan_report+0xb8/0x130
[ 297.704059] kasan_check_range+0x15c/0x240
[ 297.704061] __asan_memcpy+0x40/0xc8
[ 297.704064] trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0
[ 297.704066] __traceiter_cxl_port_aer_uncorrectable_error+0x90/0x108
[ 297.704068] cxl_ras_inject_set+0x278/0x3d0
[ 297.704070] simple_attr_write_xsigned.isra.0+0x198/0x298
[ 297.704074] simple_attr_write+0x44/0x88
[ 297.704076] debugfs_attr_write+0x78/0xd0
[ 297.704080] vfs_write+0x1f4/0x960
[ 297.704083] ksys_write+0x100/0x220
[ 297.704085] __arm64_sys_write+0x78/0xc8
[ 297.704087] invoke_syscall.constprop.0+0x150/0x200
[ 297.704090] do_el0_svc+0xd0/0x210
[ 297.704091] el0_svc+0x44/0x138
[ 297.704095] el0t_64_sync_handler+0xc0/0x108
[ 297.704097] el0t_64_sync+0x1b8/0x1c0
[ 297.704100] Allocated by task 3078:
[ 297.704102] kasan_save_stack+0x40/0x80
[ 297.704104] kasan_save_track+0x24/0x58
[ 297.704105] kasan_save_alloc_info+0x44/0x88
[ 297.704107] __kasan_kmalloc+0x108/0x110
[ 297.704108] __kmalloc_cache_noprof+0x1bc/0x588
[ 297.704111] cxl_ras_inject_set+0xcc/0x3d0
[ 297.704112] simple_attr_write_xsigned.isra.0+0x198/0x298
[ 297.704114] simple_attr_write+0x44/0x88
[ 297.704116] debugfs_attr_write+0x78/0xd0
[ 297.704117] vfs_write+0x1f4/0x960
[ 297.704119] ksys_write+0x100/0x220
[ 297.704120] __arm64_sys_write+0x78/0xc8
[ 297.704122] invoke_syscall.constprop.0+0x150/0x200
[ 297.704123] do_el0_svc+0xd0/0x210
[ 297.704124] el0_svc+0x44/0x138
[ 297.704125] el0t_64_sync_handler+0xc0/0x108
[ 297.704127] el0t_64_sync+0x1b8/0x1c0
[ 297.704129] The buggy address belongs to the object at ffff0000dd6ee100
which belongs to the cache kmalloc-rnd-09-96 of size 96
[ 297.704132] The buggy address is located 24 bytes inside of
allocated 88-byte region [ffff0000dd6ee100, ffff0000dd6ee158)
[ 297.704135] The buggy address belongs to the physical page:
[ 297.704138] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x15d6e
[ 297.704140] flags: 0x17fffc000000000(node=0|zone=2|lastcpupid=0x1ffff)
[ 297.704143] page_type: f5(slab)
[ 297.704147] raw: 017fffc000000000 ffff00008001c1c0 dead000000000100 dead000000000122
[ 297.704148] raw: 0000000000000000 0000000802000200 00000000f5000000 0000000000000000
[ 297.704149] page dumped because: kasan: bad access detected
[ 297.704150] Memory state around the buggy address:
[ 297.704151] ffff0000dd6ee000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 297.704152] ffff0000dd6ee080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 297.704153] >ffff0000dd6ee100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
[ 297.704154] ^
[ 297.704155] ffff0000dd6ee180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 297.704155] ffff0000dd6ee200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 297.704156] =================================================================
"""
Define CXL_HEADERLOG_SIZE as SZ_64. The trace record's header_log field
shrinks from 128 to 16 dwords, but only those 16 were ever real data,
the rest was always junk.
Fixes: 2f6e9c305127 ("cxl/pci: add tracepoint events for CXL RAS")
Signed-off-by: Richard Cheng <icheng@nvidia.com>
---
drivers/cxl/cxl.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 1297594beaec..f322d7c79ed2 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -158,8 +158,8 @@ static inline int ways_to_eiw(unsigned int ways, u8 *eiw)
#define CXL_RAS_CAP_CONTROL_FE_MASK GENMASK(5, 0)
#define CXL_RAS_HEADER_LOG_OFFSET 0x18
#define CXL_RAS_CAPABILITY_LENGTH 0x58
-#define CXL_HEADERLOG_SIZE SZ_512
-#define CXL_HEADERLOG_SIZE_U32 SZ_512 / sizeof(u32)
+#define CXL_HEADERLOG_SIZE SZ_64
+#define CXL_HEADERLOG_SIZE_U32 (CXL_HEADERLOG_SIZE / sizeof(u32))
/* CXL 2.0 8.2.8.1 Device Capabilities Array Register */
#define CXLDEV_CAP_ARRAY_OFFSET 0x0
base-commit: 6f3ed7fec72fc8979b2a8c7219c0a9fcfc8d07b5
--
2.43.0
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] cxl/pci: Fix out-of-bounds read of the RAS Header Log 2026-06-05 4:16 [PATCH] cxl/pci: Fix out-of-bounds read of the RAS Header Log Richard Cheng @ 2026-06-05 15:30 ` Dave Jiang 2026-06-05 16:59 ` Richard Cheng 0 siblings, 1 reply; 6+ messages in thread From: Dave Jiang @ 2026-06-05 15:30 UTC (permalink / raw) To: Richard Cheng, dave, jic23, alison.schofield, vishal.l.verma, ira.weiny, djbw Cc: linux-cxl, linux-kernel, newtonl, kristinc, kaihengf, kobak, smadhavan, vaslot On 6/4/26 9:16 PM, Richard Cheng wrote: > The CXL RAS Header Log is 64 bytes, but CXL_HEADERLOG_SIZE is SZ_512, > which is 512 bytes, not 512 bits, so the kernel treats it as 8x times > bigger. > > header_log_copy() reads 448 bytes of MMIO past the register, and > cxl_*_aer_uncorrectable_error() tracepoints memcpy 512 bytes from the > 64-byte header log. On the CPER path the source is a heap object, so the > copy runs 448 bytes past it and leaks kernel memory into a trace record > that userspace can read: I think Terry raised the same issue and this [1] is what Dan suggested for the fix as there's rasdaemon (user) impact. [1]: https://lore.kernel.org/linux-cxl/6a0e33507e961_1717cc100f6@djbw-dev.notmuch/ DJ > > """ > [ 297.704020] BUG: KASAN: slab-out-of-bounds in trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 > [ 297.704032] Read of size 512 at addr ffff0000dd6ee118 by task bash/3078 > > [ 297.704038] CPU: 116 UID: 0 PID: 3078 Comm: bash Not tainted 7.1.0-rc6+ #1 PREEMPT(full) > [ 297.704041] Hardware name: , BIOS buildbrain-gcid-sbios-45660680 Wed May 27 08:27:58 AM UTC 2026 > [ 297.704042] Call trace: > [ 297.704043] show_stack+0x24/0x50 (C) > [ 297.704049] dump_stack_lvl+0x80/0x140 > [ 297.704053] print_report+0x100/0x630 > [ 297.704057] kasan_report+0xb8/0x130 > [ 297.704059] kasan_check_range+0x15c/0x240 > [ 297.704061] __asan_memcpy+0x40/0xc8 > [ 297.704064] trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 > [ 297.704066] __traceiter_cxl_port_aer_uncorrectable_error+0x90/0x108 > [ 297.704068] cxl_ras_inject_set+0x278/0x3d0 > [ 297.704070] simple_attr_write_xsigned.isra.0+0x198/0x298 > [ 297.704074] simple_attr_write+0x44/0x88 > [ 297.704076] debugfs_attr_write+0x78/0xd0 > [ 297.704080] vfs_write+0x1f4/0x960 > [ 297.704083] ksys_write+0x100/0x220 > [ 297.704085] __arm64_sys_write+0x78/0xc8 > [ 297.704087] invoke_syscall.constprop.0+0x150/0x200 > [ 297.704090] do_el0_svc+0xd0/0x210 > [ 297.704091] el0_svc+0x44/0x138 > [ 297.704095] el0t_64_sync_handler+0xc0/0x108 > [ 297.704097] el0t_64_sync+0x1b8/0x1c0 > > [ 297.704100] Allocated by task 3078: > [ 297.704102] kasan_save_stack+0x40/0x80 > [ 297.704104] kasan_save_track+0x24/0x58 > [ 297.704105] kasan_save_alloc_info+0x44/0x88 > [ 297.704107] __kasan_kmalloc+0x108/0x110 > [ 297.704108] __kmalloc_cache_noprof+0x1bc/0x588 > [ 297.704111] cxl_ras_inject_set+0xcc/0x3d0 > [ 297.704112] simple_attr_write_xsigned.isra.0+0x198/0x298 > [ 297.704114] simple_attr_write+0x44/0x88 > [ 297.704116] debugfs_attr_write+0x78/0xd0 > [ 297.704117] vfs_write+0x1f4/0x960 > [ 297.704119] ksys_write+0x100/0x220 > [ 297.704120] __arm64_sys_write+0x78/0xc8 > [ 297.704122] invoke_syscall.constprop.0+0x150/0x200 > [ 297.704123] do_el0_svc+0xd0/0x210 > [ 297.704124] el0_svc+0x44/0x138 > [ 297.704125] el0t_64_sync_handler+0xc0/0x108 > [ 297.704127] el0t_64_sync+0x1b8/0x1c0 > > [ 297.704129] The buggy address belongs to the object at ffff0000dd6ee100 > which belongs to the cache kmalloc-rnd-09-96 of size 96 > [ 297.704132] The buggy address is located 24 bytes inside of > allocated 88-byte region [ffff0000dd6ee100, ffff0000dd6ee158) > > [ 297.704135] The buggy address belongs to the physical page: > [ 297.704138] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x15d6e > [ 297.704140] flags: 0x17fffc000000000(node=0|zone=2|lastcpupid=0x1ffff) > [ 297.704143] page_type: f5(slab) > [ 297.704147] raw: 017fffc000000000 ffff00008001c1c0 dead000000000100 dead000000000122 > [ 297.704148] raw: 0000000000000000 0000000802000200 00000000f5000000 0000000000000000 > [ 297.704149] page dumped because: kasan: bad access detected > > [ 297.704150] Memory state around the buggy address: > [ 297.704151] ffff0000dd6ee000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > [ 297.704152] ffff0000dd6ee080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > [ 297.704153] >ffff0000dd6ee100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > [ 297.704154] ^ > [ 297.704155] ffff0000dd6ee180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > [ 297.704155] ffff0000dd6ee200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > [ 297.704156] ================================================================= > """ > > Define CXL_HEADERLOG_SIZE as SZ_64. The trace record's header_log field > shrinks from 128 to 16 dwords, but only those 16 were ever real data, > the rest was always junk. > > Fixes: 2f6e9c305127 ("cxl/pci: add tracepoint events for CXL RAS") > Signed-off-by: Richard Cheng <icheng@nvidia.com> > --- > drivers/cxl/cxl.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > index 1297594beaec..f322d7c79ed2 100644 > --- a/drivers/cxl/cxl.h > +++ b/drivers/cxl/cxl.h > @@ -158,8 +158,8 @@ static inline int ways_to_eiw(unsigned int ways, u8 *eiw) > #define CXL_RAS_CAP_CONTROL_FE_MASK GENMASK(5, 0) > #define CXL_RAS_HEADER_LOG_OFFSET 0x18 > #define CXL_RAS_CAPABILITY_LENGTH 0x58 > -#define CXL_HEADERLOG_SIZE SZ_512 > -#define CXL_HEADERLOG_SIZE_U32 SZ_512 / sizeof(u32) > +#define CXL_HEADERLOG_SIZE SZ_64 > +#define CXL_HEADERLOG_SIZE_U32 (CXL_HEADERLOG_SIZE / sizeof(u32)) > > /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */ > #define CXLDEV_CAP_ARRAY_OFFSET 0x0 > > base-commit: 6f3ed7fec72fc8979b2a8c7219c0a9fcfc8d07b5 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cxl/pci: Fix out-of-bounds read of the RAS Header Log 2026-06-05 15:30 ` Dave Jiang @ 2026-06-05 16:59 ` Richard Cheng 2026-06-05 17:41 ` Bowman, Terry 0 siblings, 1 reply; 6+ messages in thread From: Richard Cheng @ 2026-06-05 16:59 UTC (permalink / raw) To: Dave Jiang Cc: dave, jic23, alison.schofield, vishal.l.verma, ira.weiny, djbw, linux-cxl, linux-kernel, newtonl, kristinc, kaihengf, kobak, smadhavan, vaslot On Fri, Jun 05, 2026 at 08:30:55AM +0800, Dave Jiang wrote: > > > On 6/4/26 9:16 PM, Richard Cheng wrote: > > The CXL RAS Header Log is 64 bytes, but CXL_HEADERLOG_SIZE is SZ_512, > > which is 512 bytes, not 512 bits, so the kernel treats it as 8x times > > bigger. > > > > header_log_copy() reads 448 bytes of MMIO past the register, and > > cxl_*_aer_uncorrectable_error() tracepoints memcpy 512 bytes from the > > 64-byte header log. On the CPER path the source is a heap object, so the > > copy runs 448 bytes past it and leaks kernel memory into a trace record > > that userspace can read: > > I think Terry raised the same issue and this [1] is what Dan suggested for the fix as there's rasdaemon (user) impact. > > [1]: https://lore.kernel.org/linux-cxl/6a0e33507e961_1717cc100f6@djbw-dev.notmuch/ > > DJ Hi Dave, I see, so is he gonna do the fix or I can send a v2 with the suggested approach ? Best regards, Richard Cheng. > > > > > """ > > [ 297.704020] BUG: KASAN: slab-out-of-bounds in trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 > > [ 297.704032] Read of size 512 at addr ffff0000dd6ee118 by task bash/3078 > > > > [ 297.704038] CPU: 116 UID: 0 PID: 3078 Comm: bash Not tainted 7.1.0-rc6+ #1 PREEMPT(full) > > [ 297.704041] Hardware name: , BIOS buildbrain-gcid-sbios-45660680 Wed May 27 08:27:58 AM UTC 2026 > > [ 297.704042] Call trace: > > [ 297.704043] show_stack+0x24/0x50 (C) > > [ 297.704049] dump_stack_lvl+0x80/0x140 > > [ 297.704053] print_report+0x100/0x630 > > [ 297.704057] kasan_report+0xb8/0x130 > > [ 297.704059] kasan_check_range+0x15c/0x240 > > [ 297.704061] __asan_memcpy+0x40/0xc8 > > [ 297.704064] trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 > > [ 297.704066] __traceiter_cxl_port_aer_uncorrectable_error+0x90/0x108 > > [ 297.704068] cxl_ras_inject_set+0x278/0x3d0 > > [ 297.704070] simple_attr_write_xsigned.isra.0+0x198/0x298 > > [ 297.704074] simple_attr_write+0x44/0x88 > > [ 297.704076] debugfs_attr_write+0x78/0xd0 > > [ 297.704080] vfs_write+0x1f4/0x960 > > [ 297.704083] ksys_write+0x100/0x220 > > [ 297.704085] __arm64_sys_write+0x78/0xc8 > > [ 297.704087] invoke_syscall.constprop.0+0x150/0x200 > > [ 297.704090] do_el0_svc+0xd0/0x210 > > [ 297.704091] el0_svc+0x44/0x138 > > [ 297.704095] el0t_64_sync_handler+0xc0/0x108 > > [ 297.704097] el0t_64_sync+0x1b8/0x1c0 > > > > [ 297.704100] Allocated by task 3078: > > [ 297.704102] kasan_save_stack+0x40/0x80 > > [ 297.704104] kasan_save_track+0x24/0x58 > > [ 297.704105] kasan_save_alloc_info+0x44/0x88 > > [ 297.704107] __kasan_kmalloc+0x108/0x110 > > [ 297.704108] __kmalloc_cache_noprof+0x1bc/0x588 > > [ 297.704111] cxl_ras_inject_set+0xcc/0x3d0 > > [ 297.704112] simple_attr_write_xsigned.isra.0+0x198/0x298 > > [ 297.704114] simple_attr_write+0x44/0x88 > > [ 297.704116] debugfs_attr_write+0x78/0xd0 > > [ 297.704117] vfs_write+0x1f4/0x960 > > [ 297.704119] ksys_write+0x100/0x220 > > [ 297.704120] __arm64_sys_write+0x78/0xc8 > > [ 297.704122] invoke_syscall.constprop.0+0x150/0x200 > > [ 297.704123] do_el0_svc+0xd0/0x210 > > [ 297.704124] el0_svc+0x44/0x138 > > [ 297.704125] el0t_64_sync_handler+0xc0/0x108 > > [ 297.704127] el0t_64_sync+0x1b8/0x1c0 > > > > [ 297.704129] The buggy address belongs to the object at ffff0000dd6ee100 > > which belongs to the cache kmalloc-rnd-09-96 of size 96 > > [ 297.704132] The buggy address is located 24 bytes inside of > > allocated 88-byte region [ffff0000dd6ee100, ffff0000dd6ee158) > > > > [ 297.704135] The buggy address belongs to the physical page: > > [ 297.704138] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x15d6e > > [ 297.704140] flags: 0x17fffc000000000(node=0|zone=2|lastcpupid=0x1ffff) > > [ 297.704143] page_type: f5(slab) > > [ 297.704147] raw: 017fffc000000000 ffff00008001c1c0 dead000000000100 dead000000000122 > > [ 297.704148] raw: 0000000000000000 0000000802000200 00000000f5000000 0000000000000000 > > [ 297.704149] page dumped because: kasan: bad access detected > > > > [ 297.704150] Memory state around the buggy address: > > [ 297.704151] ffff0000dd6ee000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > [ 297.704152] ffff0000dd6ee080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > [ 297.704153] >ffff0000dd6ee100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > [ 297.704154] ^ > > [ 297.704155] ffff0000dd6ee180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > [ 297.704155] ffff0000dd6ee200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > [ 297.704156] ================================================================= > > """ > > > > Define CXL_HEADERLOG_SIZE as SZ_64. The trace record's header_log field > > shrinks from 128 to 16 dwords, but only those 16 were ever real data, > > the rest was always junk. > > > > Fixes: 2f6e9c305127 ("cxl/pci: add tracepoint events for CXL RAS") > > Signed-off-by: Richard Cheng <icheng@nvidia.com> > > --- > > drivers/cxl/cxl.h | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > > index 1297594beaec..f322d7c79ed2 100644 > > --- a/drivers/cxl/cxl.h > > +++ b/drivers/cxl/cxl.h > > @@ -158,8 +158,8 @@ static inline int ways_to_eiw(unsigned int ways, u8 *eiw) > > #define CXL_RAS_CAP_CONTROL_FE_MASK GENMASK(5, 0) > > #define CXL_RAS_HEADER_LOG_OFFSET 0x18 > > #define CXL_RAS_CAPABILITY_LENGTH 0x58 > > -#define CXL_HEADERLOG_SIZE SZ_512 > > -#define CXL_HEADERLOG_SIZE_U32 SZ_512 / sizeof(u32) > > +#define CXL_HEADERLOG_SIZE SZ_64 > > +#define CXL_HEADERLOG_SIZE_U32 (CXL_HEADERLOG_SIZE / sizeof(u32)) > > > > /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */ > > #define CXLDEV_CAP_ARRAY_OFFSET 0x0 > > > > base-commit: 6f3ed7fec72fc8979b2a8c7219c0a9fcfc8d07b5 > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cxl/pci: Fix out-of-bounds read of the RAS Header Log 2026-06-05 16:59 ` Richard Cheng @ 2026-06-05 17:41 ` Bowman, Terry 2026-06-05 17:59 ` Richard Cheng 0 siblings, 1 reply; 6+ messages in thread From: Bowman, Terry @ 2026-06-05 17:41 UTC (permalink / raw) To: Richard Cheng, Dave Jiang Cc: dave, jic23, alison.schofield, vishal.l.verma, ira.weiny, djbw, linux-cxl, linux-kernel, newtonl, kristinc, kaihengf, kobak, smadhavan, vaslot On 6/5/2026 11:59 AM, Richard Cheng wrote: > On Fri, Jun 05, 2026 at 08:30:55AM +0800, Dave Jiang wrote: >> >> >> On 6/4/26 9:16 PM, Richard Cheng wrote: >>> The CXL RAS Header Log is 64 bytes, but CXL_HEADERLOG_SIZE is SZ_512, >>> which is 512 bytes, not 512 bits, so the kernel treats it as 8x times >>> bigger. >>> >>> header_log_copy() reads 448 bytes of MMIO past the register, and >>> cxl_*_aer_uncorrectable_error() tracepoints memcpy 512 bytes from the >>> 64-byte header log. On the CPER path the source is a heap object, so the >>> copy runs 448 bytes past it and leaks kernel memory into a trace record >>> that userspace can read: >> >> I think Terry raised the same issue and this [1] is what Dan suggested for the fix as there's rasdaemon (user) impact. >> >> [1]: https://lore.kernel.org/linux-cxl/6a0e33507e961_1717cc100f6@djbw-dev.notmuch/ >> >> DJ > > Hi Dave, > > I see, so is he gonna do the fix or I can send a v2 with the suggested approach ? > > Best regards, > Richard Cheng. > Hi Richard, I will send that fix today. Regards, Terry >> >>> >>> """ >>> [ 297.704020] BUG: KASAN: slab-out-of-bounds in trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 >>> [ 297.704032] Read of size 512 at addr ffff0000dd6ee118 by task bash/3078 >>> >>> [ 297.704038] CPU: 116 UID: 0 PID: 3078 Comm: bash Not tainted 7.1.0-rc6+ #1 PREEMPT(full) >>> [ 297.704041] Hardware name: , BIOS buildbrain-gcid-sbios-45660680 Wed May 27 08:27:58 AM UTC 2026 >>> [ 297.704042] Call trace: >>> [ 297.704043] show_stack+0x24/0x50 (C) >>> [ 297.704049] dump_stack_lvl+0x80/0x140 >>> [ 297.704053] print_report+0x100/0x630 >>> [ 297.704057] kasan_report+0xb8/0x130 >>> [ 297.704059] kasan_check_range+0x15c/0x240 >>> [ 297.704061] __asan_memcpy+0x40/0xc8 >>> [ 297.704064] trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 >>> [ 297.704066] __traceiter_cxl_port_aer_uncorrectable_error+0x90/0x108 >>> [ 297.704068] cxl_ras_inject_set+0x278/0x3d0 >>> [ 297.704070] simple_attr_write_xsigned.isra.0+0x198/0x298 >>> [ 297.704074] simple_attr_write+0x44/0x88 >>> [ 297.704076] debugfs_attr_write+0x78/0xd0 >>> [ 297.704080] vfs_write+0x1f4/0x960 >>> [ 297.704083] ksys_write+0x100/0x220 >>> [ 297.704085] __arm64_sys_write+0x78/0xc8 >>> [ 297.704087] invoke_syscall.constprop.0+0x150/0x200 >>> [ 297.704090] do_el0_svc+0xd0/0x210 >>> [ 297.704091] el0_svc+0x44/0x138 >>> [ 297.704095] el0t_64_sync_handler+0xc0/0x108 >>> [ 297.704097] el0t_64_sync+0x1b8/0x1c0 >>> >>> [ 297.704100] Allocated by task 3078: >>> [ 297.704102] kasan_save_stack+0x40/0x80 >>> [ 297.704104] kasan_save_track+0x24/0x58 >>> [ 297.704105] kasan_save_alloc_info+0x44/0x88 >>> [ 297.704107] __kasan_kmalloc+0x108/0x110 >>> [ 297.704108] __kmalloc_cache_noprof+0x1bc/0x588 >>> [ 297.704111] cxl_ras_inject_set+0xcc/0x3d0 >>> [ 297.704112] simple_attr_write_xsigned.isra.0+0x198/0x298 >>> [ 297.704114] simple_attr_write+0x44/0x88 >>> [ 297.704116] debugfs_attr_write+0x78/0xd0 >>> [ 297.704117] vfs_write+0x1f4/0x960 >>> [ 297.704119] ksys_write+0x100/0x220 >>> [ 297.704120] __arm64_sys_write+0x78/0xc8 >>> [ 297.704122] invoke_syscall.constprop.0+0x150/0x200 >>> [ 297.704123] do_el0_svc+0xd0/0x210 >>> [ 297.704124] el0_svc+0x44/0x138 >>> [ 297.704125] el0t_64_sync_handler+0xc0/0x108 >>> [ 297.704127] el0t_64_sync+0x1b8/0x1c0 >>> >>> [ 297.704129] The buggy address belongs to the object at ffff0000dd6ee100 >>> which belongs to the cache kmalloc-rnd-09-96 of size 96 >>> [ 297.704132] The buggy address is located 24 bytes inside of >>> allocated 88-byte region [ffff0000dd6ee100, ffff0000dd6ee158) >>> >>> [ 297.704135] The buggy address belongs to the physical page: >>> [ 297.704138] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x15d6e >>> [ 297.704140] flags: 0x17fffc000000000(node=0|zone=2|lastcpupid=0x1ffff) >>> [ 297.704143] page_type: f5(slab) >>> [ 297.704147] raw: 017fffc000000000 ffff00008001c1c0 dead000000000100 dead000000000122 >>> [ 297.704148] raw: 0000000000000000 0000000802000200 00000000f5000000 0000000000000000 >>> [ 297.704149] page dumped because: kasan: bad access detected >>> >>> [ 297.704150] Memory state around the buggy address: >>> [ 297.704151] ffff0000dd6ee000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>> [ 297.704152] ffff0000dd6ee080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>> [ 297.704153] >ffff0000dd6ee100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc >>> [ 297.704154] ^ >>> [ 297.704155] ffff0000dd6ee180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>> [ 297.704155] ffff0000dd6ee200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>> [ 297.704156] ================================================================= >>> """ >>> >>> Define CXL_HEADERLOG_SIZE as SZ_64. The trace record's header_log field >>> shrinks from 128 to 16 dwords, but only those 16 were ever real data, >>> the rest was always junk. >>> >>> Fixes: 2f6e9c305127 ("cxl/pci: add tracepoint events for CXL RAS") >>> Signed-off-by: Richard Cheng <icheng@nvidia.com> >>> --- >>> drivers/cxl/cxl.h | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h >>> index 1297594beaec..f322d7c79ed2 100644 >>> --- a/drivers/cxl/cxl.h >>> +++ b/drivers/cxl/cxl.h >>> @@ -158,8 +158,8 @@ static inline int ways_to_eiw(unsigned int ways, u8 *eiw) >>> #define CXL_RAS_CAP_CONTROL_FE_MASK GENMASK(5, 0) >>> #define CXL_RAS_HEADER_LOG_OFFSET 0x18 >>> #define CXL_RAS_CAPABILITY_LENGTH 0x58 >>> -#define CXL_HEADERLOG_SIZE SZ_512 >>> -#define CXL_HEADERLOG_SIZE_U32 SZ_512 / sizeof(u32) >>> +#define CXL_HEADERLOG_SIZE SZ_64 >>> +#define CXL_HEADERLOG_SIZE_U32 (CXL_HEADERLOG_SIZE / sizeof(u32)) >>> >>> /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */ >>> #define CXLDEV_CAP_ARRAY_OFFSET 0x0 >>> >>> base-commit: 6f3ed7fec72fc8979b2a8c7219c0a9fcfc8d07b5 >> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cxl/pci: Fix out-of-bounds read of the RAS Header Log 2026-06-05 17:41 ` Bowman, Terry @ 2026-06-05 17:59 ` Richard Cheng 2026-06-05 18:09 ` Bowman, Terry 0 siblings, 1 reply; 6+ messages in thread From: Richard Cheng @ 2026-06-05 17:59 UTC (permalink / raw) To: Bowman, Terry Cc: Dave Jiang, dave, jic23, alison.schofield, vishal.l.verma, ira.weiny, djbw, linux-cxl, linux-kernel, newtonl, kristinc, kaihengf, kobak, smadhavan, vaslot On Fri, Jun 05, 2026 at 12:41:15PM +0800, Bowman, Terry wrote: > On 6/5/2026 11:59 AM, Richard Cheng wrote: > > On Fri, Jun 05, 2026 at 08:30:55AM +0800, Dave Jiang wrote: > >> > >> > >> On 6/4/26 9:16 PM, Richard Cheng wrote: > >>> The CXL RAS Header Log is 64 bytes, but CXL_HEADERLOG_SIZE is SZ_512, > >>> which is 512 bytes, not 512 bits, so the kernel treats it as 8x times > >>> bigger. > >>> > >>> header_log_copy() reads 448 bytes of MMIO past the register, and > >>> cxl_*_aer_uncorrectable_error() tracepoints memcpy 512 bytes from the > >>> 64-byte header log. On the CPER path the source is a heap object, so the > >>> copy runs 448 bytes past it and leaks kernel memory into a trace record > >>> that userspace can read: > >> > >> I think Terry raised the same issue and this [1] is what Dan suggested for the fix as there's rasdaemon (user) impact. > >> > >> [1]: https://lore.kernel.org/linux-cxl/6a0e33507e961_1717cc100f6@djbw-dev.notmuch/ > >> > >> DJ > > > > Hi Dave, > > > > I see, so is he gonna do the fix or I can send a v2 with the suggested approach ? > > > > Best regards, > > Richard Cheng. > > > > Hi Richard, > > I will send that fix today. > > Regards, > Terry > Hi Terry, That would be awesome ! If you don't mind, can you add me in the cc list ? I would love to learn from your approach. Thanks, Richard Cheng > >> > >>> > >>> """ > >>> [ 297.704020] BUG: KASAN: slab-out-of-bounds in trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 > >>> [ 297.704032] Read of size 512 at addr ffff0000dd6ee118 by task bash/3078 > >>> > >>> [ 297.704038] CPU: 116 UID: 0 PID: 3078 Comm: bash Not tainted 7.1.0-rc6+ #1 PREEMPT(full) > >>> [ 297.704041] Hardware name: , BIOS buildbrain-gcid-sbios-45660680 Wed May 27 08:27:58 AM UTC 2026 > >>> [ 297.704042] Call trace: > >>> [ 297.704043] show_stack+0x24/0x50 (C) > >>> [ 297.704049] dump_stack_lvl+0x80/0x140 > >>> [ 297.704053] print_report+0x100/0x630 > >>> [ 297.704057] kasan_report+0xb8/0x130 > >>> [ 297.704059] kasan_check_range+0x15c/0x240 > >>> [ 297.704061] __asan_memcpy+0x40/0xc8 > >>> [ 297.704064] trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 > >>> [ 297.704066] __traceiter_cxl_port_aer_uncorrectable_error+0x90/0x108 > >>> [ 297.704068] cxl_ras_inject_set+0x278/0x3d0 > >>> [ 297.704070] simple_attr_write_xsigned.isra.0+0x198/0x298 > >>> [ 297.704074] simple_attr_write+0x44/0x88 > >>> [ 297.704076] debugfs_attr_write+0x78/0xd0 > >>> [ 297.704080] vfs_write+0x1f4/0x960 > >>> [ 297.704083] ksys_write+0x100/0x220 > >>> [ 297.704085] __arm64_sys_write+0x78/0xc8 > >>> [ 297.704087] invoke_syscall.constprop.0+0x150/0x200 > >>> [ 297.704090] do_el0_svc+0xd0/0x210 > >>> [ 297.704091] el0_svc+0x44/0x138 > >>> [ 297.704095] el0t_64_sync_handler+0xc0/0x108 > >>> [ 297.704097] el0t_64_sync+0x1b8/0x1c0 > >>> > >>> [ 297.704100] Allocated by task 3078: > >>> [ 297.704102] kasan_save_stack+0x40/0x80 > >>> [ 297.704104] kasan_save_track+0x24/0x58 > >>> [ 297.704105] kasan_save_alloc_info+0x44/0x88 > >>> [ 297.704107] __kasan_kmalloc+0x108/0x110 > >>> [ 297.704108] __kmalloc_cache_noprof+0x1bc/0x588 > >>> [ 297.704111] cxl_ras_inject_set+0xcc/0x3d0 > >>> [ 297.704112] simple_attr_write_xsigned.isra.0+0x198/0x298 > >>> [ 297.704114] simple_attr_write+0x44/0x88 > >>> [ 297.704116] debugfs_attr_write+0x78/0xd0 > >>> [ 297.704117] vfs_write+0x1f4/0x960 > >>> [ 297.704119] ksys_write+0x100/0x220 > >>> [ 297.704120] __arm64_sys_write+0x78/0xc8 > >>> [ 297.704122] invoke_syscall.constprop.0+0x150/0x200 > >>> [ 297.704123] do_el0_svc+0xd0/0x210 > >>> [ 297.704124] el0_svc+0x44/0x138 > >>> [ 297.704125] el0t_64_sync_handler+0xc0/0x108 > >>> [ 297.704127] el0t_64_sync+0x1b8/0x1c0 > >>> > >>> [ 297.704129] The buggy address belongs to the object at ffff0000dd6ee100 > >>> which belongs to the cache kmalloc-rnd-09-96 of size 96 > >>> [ 297.704132] The buggy address is located 24 bytes inside of > >>> allocated 88-byte region [ffff0000dd6ee100, ffff0000dd6ee158) > >>> > >>> [ 297.704135] The buggy address belongs to the physical page: > >>> [ 297.704138] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x15d6e > >>> [ 297.704140] flags: 0x17fffc000000000(node=0|zone=2|lastcpupid=0x1ffff) > >>> [ 297.704143] page_type: f5(slab) > >>> [ 297.704147] raw: 017fffc000000000 ffff00008001c1c0 dead000000000100 dead000000000122 > >>> [ 297.704148] raw: 0000000000000000 0000000802000200 00000000f5000000 0000000000000000 > >>> [ 297.704149] page dumped because: kasan: bad access detected > >>> > >>> [ 297.704150] Memory state around the buggy address: > >>> [ 297.704151] ffff0000dd6ee000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > >>> [ 297.704152] ffff0000dd6ee080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > >>> [ 297.704153] >ffff0000dd6ee100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > >>> [ 297.704154] ^ > >>> [ 297.704155] ffff0000dd6ee180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > >>> [ 297.704155] ffff0000dd6ee200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > >>> [ 297.704156] ================================================================= > >>> """ > >>> > >>> Define CXL_HEADERLOG_SIZE as SZ_64. The trace record's header_log field > >>> shrinks from 128 to 16 dwords, but only those 16 were ever real data, > >>> the rest was always junk. > >>> > >>> Fixes: 2f6e9c305127 ("cxl/pci: add tracepoint events for CXL RAS") > >>> Signed-off-by: Richard Cheng <icheng@nvidia.com> > >>> --- > >>> drivers/cxl/cxl.h | 4 ++-- > >>> 1 file changed, 2 insertions(+), 2 deletions(-) > >>> > >>> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > >>> index 1297594beaec..f322d7c79ed2 100644 > >>> --- a/drivers/cxl/cxl.h > >>> +++ b/drivers/cxl/cxl.h > >>> @@ -158,8 +158,8 @@ static inline int ways_to_eiw(unsigned int ways, u8 *eiw) > >>> #define CXL_RAS_CAP_CONTROL_FE_MASK GENMASK(5, 0) > >>> #define CXL_RAS_HEADER_LOG_OFFSET 0x18 > >>> #define CXL_RAS_CAPABILITY_LENGTH 0x58 > >>> -#define CXL_HEADERLOG_SIZE SZ_512 > >>> -#define CXL_HEADERLOG_SIZE_U32 SZ_512 / sizeof(u32) > >>> +#define CXL_HEADERLOG_SIZE SZ_64 > >>> +#define CXL_HEADERLOG_SIZE_U32 (CXL_HEADERLOG_SIZE / sizeof(u32)) > >>> > >>> /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */ > >>> #define CXLDEV_CAP_ARRAY_OFFSET 0x0 > >>> > >>> base-commit: 6f3ed7fec72fc8979b2a8c7219c0a9fcfc8d07b5 > >> > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cxl/pci: Fix out-of-bounds read of the RAS Header Log 2026-06-05 17:59 ` Richard Cheng @ 2026-06-05 18:09 ` Bowman, Terry 0 siblings, 0 replies; 6+ messages in thread From: Bowman, Terry @ 2026-06-05 18:09 UTC (permalink / raw) To: Richard Cheng Cc: Dave Jiang, dave, jic23, alison.schofield, vishal.l.verma, ira.weiny, djbw, linux-cxl, linux-kernel, newtonl, kristinc, kaihengf, kobak, smadhavan, vaslot On 6/5/2026 12:59 PM, Richard Cheng wrote: > On Fri, Jun 05, 2026 at 12:41:15PM +0800, Bowman, Terry wrote: >> On 6/5/2026 11:59 AM, Richard Cheng wrote: >>> On Fri, Jun 05, 2026 at 08:30:55AM +0800, Dave Jiang wrote: >>>> >>>> >>>> On 6/4/26 9:16 PM, Richard Cheng wrote: >>>>> The CXL RAS Header Log is 64 bytes, but CXL_HEADERLOG_SIZE is SZ_512, >>>>> which is 512 bytes, not 512 bits, so the kernel treats it as 8x times >>>>> bigger. >>>>> >>>>> header_log_copy() reads 448 bytes of MMIO past the register, and >>>>> cxl_*_aer_uncorrectable_error() tracepoints memcpy 512 bytes from the >>>>> 64-byte header log. On the CPER path the source is a heap object, so the >>>>> copy runs 448 bytes past it and leaks kernel memory into a trace record >>>>> that userspace can read: >>>> >>>> I think Terry raised the same issue and this [1] is what Dan suggested for the fix as there's rasdaemon (user) impact. >>>> >>>> [1]: https://lore.kernel.org/linux-cxl/6a0e33507e961_1717cc100f6@djbw-dev.notmuch/ >>>> >>>> DJ >>> >>> Hi Dave, >>> >>> I see, so is he gonna do the fix or I can send a v2 with the suggested approach ? >>> >>> Best regards, >>> Richard Cheng. >>> >> >> Hi Richard, >> >> I will send that fix today. >> >> Regards, >> Terry >> > > Hi Terry, > > That would be awesome ! > If you don't mind, can you add me in the cc list ? > I would love to learn from your approach. > > Thanks, > Richard Cheng > Hi Richard, I just sent but missed adding you to the list. My apologies. The patch is here: https://lore.kernel.org/linux-cxl/20260605180610.2249458-1-terry.bowman@amd.com/T/#u Regards, Terry >>>> >>>>> >>>>> """ >>>>> [ 297.704020] BUG: KASAN: slab-out-of-bounds in trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 >>>>> [ 297.704032] Read of size 512 at addr ffff0000dd6ee118 by task bash/3078 >>>>> >>>>> [ 297.704038] CPU: 116 UID: 0 PID: 3078 Comm: bash Not tainted 7.1.0-rc6+ #1 PREEMPT(full) >>>>> [ 297.704041] Hardware name: , BIOS buildbrain-gcid-sbios-45660680 Wed May 27 08:27:58 AM UTC 2026 >>>>> [ 297.704042] Call trace: >>>>> [ 297.704043] show_stack+0x24/0x50 (C) >>>>> [ 297.704049] dump_stack_lvl+0x80/0x140 >>>>> [ 297.704053] print_report+0x100/0x630 >>>>> [ 297.704057] kasan_report+0xb8/0x130 >>>>> [ 297.704059] kasan_check_range+0x15c/0x240 >>>>> [ 297.704061] __asan_memcpy+0x40/0xc8 >>>>> [ 297.704064] trace_event_raw_event_cxl_port_aer_uncorrectable_error+0x318/0x4b0 >>>>> [ 297.704066] __traceiter_cxl_port_aer_uncorrectable_error+0x90/0x108 >>>>> [ 297.704068] cxl_ras_inject_set+0x278/0x3d0 >>>>> [ 297.704070] simple_attr_write_xsigned.isra.0+0x198/0x298 >>>>> [ 297.704074] simple_attr_write+0x44/0x88 >>>>> [ 297.704076] debugfs_attr_write+0x78/0xd0 >>>>> [ 297.704080] vfs_write+0x1f4/0x960 >>>>> [ 297.704083] ksys_write+0x100/0x220 >>>>> [ 297.704085] __arm64_sys_write+0x78/0xc8 >>>>> [ 297.704087] invoke_syscall.constprop.0+0x150/0x200 >>>>> [ 297.704090] do_el0_svc+0xd0/0x210 >>>>> [ 297.704091] el0_svc+0x44/0x138 >>>>> [ 297.704095] el0t_64_sync_handler+0xc0/0x108 >>>>> [ 297.704097] el0t_64_sync+0x1b8/0x1c0 >>>>> >>>>> [ 297.704100] Allocated by task 3078: >>>>> [ 297.704102] kasan_save_stack+0x40/0x80 >>>>> [ 297.704104] kasan_save_track+0x24/0x58 >>>>> [ 297.704105] kasan_save_alloc_info+0x44/0x88 >>>>> [ 297.704107] __kasan_kmalloc+0x108/0x110 >>>>> [ 297.704108] __kmalloc_cache_noprof+0x1bc/0x588 >>>>> [ 297.704111] cxl_ras_inject_set+0xcc/0x3d0 >>>>> [ 297.704112] simple_attr_write_xsigned.isra.0+0x198/0x298 >>>>> [ 297.704114] simple_attr_write+0x44/0x88 >>>>> [ 297.704116] debugfs_attr_write+0x78/0xd0 >>>>> [ 297.704117] vfs_write+0x1f4/0x960 >>>>> [ 297.704119] ksys_write+0x100/0x220 >>>>> [ 297.704120] __arm64_sys_write+0x78/0xc8 >>>>> [ 297.704122] invoke_syscall.constprop.0+0x150/0x200 >>>>> [ 297.704123] do_el0_svc+0xd0/0x210 >>>>> [ 297.704124] el0_svc+0x44/0x138 >>>>> [ 297.704125] el0t_64_sync_handler+0xc0/0x108 >>>>> [ 297.704127] el0t_64_sync+0x1b8/0x1c0 >>>>> >>>>> [ 297.704129] The buggy address belongs to the object at ffff0000dd6ee100 >>>>> which belongs to the cache kmalloc-rnd-09-96 of size 96 >>>>> [ 297.704132] The buggy address is located 24 bytes inside of >>>>> allocated 88-byte region [ffff0000dd6ee100, ffff0000dd6ee158) >>>>> >>>>> [ 297.704135] The buggy address belongs to the physical page: >>>>> [ 297.704138] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x15d6e >>>>> [ 297.704140] flags: 0x17fffc000000000(node=0|zone=2|lastcpupid=0x1ffff) >>>>> [ 297.704143] page_type: f5(slab) >>>>> [ 297.704147] raw: 017fffc000000000 ffff00008001c1c0 dead000000000100 dead000000000122 >>>>> [ 297.704148] raw: 0000000000000000 0000000802000200 00000000f5000000 0000000000000000 >>>>> [ 297.704149] page dumped because: kasan: bad access detected >>>>> >>>>> [ 297.704150] Memory state around the buggy address: >>>>> [ 297.704151] ffff0000dd6ee000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>>>> [ 297.704152] ffff0000dd6ee080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>>>> [ 297.704153] >ffff0000dd6ee100: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc >>>>> [ 297.704154] ^ >>>>> [ 297.704155] ffff0000dd6ee180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>>>> [ 297.704155] ffff0000dd6ee200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>>>> [ 297.704156] ================================================================= >>>>> """ >>>>> >>>>> Define CXL_HEADERLOG_SIZE as SZ_64. The trace record's header_log field >>>>> shrinks from 128 to 16 dwords, but only those 16 were ever real data, >>>>> the rest was always junk. >>>>> >>>>> Fixes: 2f6e9c305127 ("cxl/pci: add tracepoint events for CXL RAS") >>>>> Signed-off-by: Richard Cheng <icheng@nvidia.com> >>>>> --- >>>>> drivers/cxl/cxl.h | 4 ++-- >>>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>>> >>>>> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h >>>>> index 1297594beaec..f322d7c79ed2 100644 >>>>> --- a/drivers/cxl/cxl.h >>>>> +++ b/drivers/cxl/cxl.h >>>>> @@ -158,8 +158,8 @@ static inline int ways_to_eiw(unsigned int ways, u8 *eiw) >>>>> #define CXL_RAS_CAP_CONTROL_FE_MASK GENMASK(5, 0) >>>>> #define CXL_RAS_HEADER_LOG_OFFSET 0x18 >>>>> #define CXL_RAS_CAPABILITY_LENGTH 0x58 >>>>> -#define CXL_HEADERLOG_SIZE SZ_512 >>>>> -#define CXL_HEADERLOG_SIZE_U32 SZ_512 / sizeof(u32) >>>>> +#define CXL_HEADERLOG_SIZE SZ_64 >>>>> +#define CXL_HEADERLOG_SIZE_U32 (CXL_HEADERLOG_SIZE / sizeof(u32)) >>>>> >>>>> /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */ >>>>> #define CXLDEV_CAP_ARRAY_OFFSET 0x0 >>>>> >>>>> base-commit: 6f3ed7fec72fc8979b2a8c7219c0a9fcfc8d07b5 >>>> >> ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-06-05 18:09 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2026-06-05 4:16 [PATCH] cxl/pci: Fix out-of-bounds read of the RAS Header Log Richard Cheng 2026-06-05 15:30 ` Dave Jiang 2026-06-05 16:59 ` Richard Cheng 2026-06-05 17:41 ` Bowman, Terry 2026-06-05 17:59 ` Richard Cheng 2026-06-05 18:09 ` Bowman, Terry
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